From 0a9b73da05ef07360de3c945f9a7ecf57c3ef0d9 Mon Sep 17 00:00:00 2001
From: fcarreiro <facundo@aztecprotocol.com>
Date: Wed, 7 Feb 2024 09:57:40 +0000
Subject: [PATCH 01/12] chore(avm): add SET serialize comments and simplify
 signature

---
 .../simulator/src/avm/opcodes/instruction.ts    | 17 ++++++++++-------
 .../simulator/src/avm/opcodes/memory.ts         |  7 +++----
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/yarn-project/simulator/src/avm/opcodes/instruction.ts b/yarn-project/simulator/src/avm/opcodes/instruction.ts
index 3f4cf27f7de..f968ad88d2b 100644
--- a/yarn-project/simulator/src/avm/opcodes/instruction.ts
+++ b/yarn-project/simulator/src/avm/opcodes/instruction.ts
@@ -1,4 +1,4 @@
-import { assert } from 'console';
+import { strict as assert } from 'assert';
 
 import type { AvmContext } from '../avm_context.js';
 import { BufferCursor } from '../serialization/buffer_cursor.js';
@@ -39,7 +39,7 @@ export abstract class Instruction {
    * @returns The serialized instruction.
    */
   public serialize(this: any): Buffer {
-    assert(this instanceof Instruction);
+    assert(!!this.constructor.wireFormat, 'wireFormat must be defined on the class');
     return serialize(this.constructor.wireFormat, this);
   }
 
@@ -50,12 +50,15 @@ export abstract class Instruction {
    * @param buf Buffer to read from.
    * @returns Constructed instance of Class.
    */
-  public static deserialize<T extends { new (...args: any[]): InstanceType<T>; wireFormat: OperandType[] }>(
-    this: T,
-    buf: BufferCursor | Buffer,
-  ): InstanceType<T> {
+  public static deserialize(this: InstructionConstructor, buf: BufferCursor | Buffer): Instruction {
+    assert(!!this.wireFormat, 'wireFormat must be defined on the instruction class');
     const res = deserialize(buf, this.wireFormat);
-    const args = res.slice(1) as ConstructorParameters<T>; // Remove opcode.
+    const args = res.slice(1); // Remove opcode.
     return new this(...args);
   }
 }
+
+type InstructionConstructor = {
+  new (...args: any[]): Instruction;
+  wireFormat?: OperandType[];
+};
diff --git a/yarn-project/simulator/src/avm/opcodes/memory.ts b/yarn-project/simulator/src/avm/opcodes/memory.ts
index 06e7b615332..6f181e52f96 100644
--- a/yarn-project/simulator/src/avm/opcodes/memory.ts
+++ b/yarn-project/simulator/src/avm/opcodes/memory.ts
@@ -43,6 +43,7 @@ export class Set extends Instruction {
     super();
   }
 
+  /** We need to use a custom serialize function because of the variable length of the value. */
   public serialize(): Buffer {
     const format: OperandType[] = [
       ...Set.wireFormatBeforeConst,
@@ -52,10 +53,8 @@ export class Set extends Instruction {
     return serialize(format, this);
   }
 
-  public static deserialize<T extends { new (...args: any[]): InstanceType<T> }>(
-    this: T,
-    buf: BufferCursor | Buffer,
-  ): InstanceType<T> {
+  /** We need to use a custom deserialize function because of the variable length of the value. */
+  public static deserialize(this: typeof Set, buf: BufferCursor | Buffer): Set {
     if (buf instanceof Buffer) {
       buf = new BufferCursor(buf);
     }

From 6648b29df0c6b0f6e9479f3421ed3cf712cae72e Mon Sep 17 00:00:00 2001
From: fcarreiro <facundo@aztecprotocol.com>
Date: Wed, 7 Feb 2024 15:19:08 +0000
Subject: [PATCH 02/12] chore(avm): add/improve tests for AvmContext, tagged
 memory, etc

---
 yarn-project/simulator/package.json           |   2 +
 .../simulator/src/avm/avm_context.test.ts     |  57 +++-
 .../src/avm/avm_execution_environment.test.ts |  53 ++--
 .../src/avm/avm_memory_types.test.ts          | 190 ++++++++++-
 .../simulator/src/avm/avm_memory_types.ts     |  15 +-
 .../simulator/src/avm/fixtures/index.ts       |   8 +
 .../src/avm/opcodes/arithmetic.test.ts        |  10 +-
 .../avm/opcodes/environment_getters.test.ts   | 298 ++++--------------
 yarn-project/yarn.lock                        |  11 +
 9 files changed, 348 insertions(+), 296 deletions(-)

diff --git a/yarn-project/simulator/package.json b/yarn-project/simulator/package.json
index 0f55f685910..0a84d51627b 100644
--- a/yarn-project/simulator/package.json
+++ b/yarn-project/simulator/package.json
@@ -45,10 +45,12 @@
     "@jest/globals": "^29.5.0",
     "@types/jest": "^29.5.0",
     "@types/levelup": "^5.1.3",
+    "@types/lodash.merge": "^4.6.9",
     "@types/memdown": "^3.0.2",
     "@types/node": "^18.7.23",
     "jest": "^29.5.0",
     "jest-mock-extended": "^3.0.4",
+    "lodash.merge": "^4.6.2",
     "ts-jest": "^29.1.0",
     "ts-node": "^10.9.1",
     "typescript": "^5.0.4",
diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index 6f198fa0bb8..f54fe99a358 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -1,18 +1,55 @@
-// import { AztecAddress, Fr } from '@aztec/circuits.js';
-// import { initContext } from './fixtures/index.js';
+import { AztecAddress, Fr } from '@aztec/circuits.js';
+
+import { allSameExcept, initContext } from './fixtures/index.js';
 
 describe('Avm Context', () => {
   it('New call should fork context correctly', () => {
-    // const context = initContext();
-    // const newAddress = AztecAddress.random();
-    // const newCalldata = [new Fr(1), new Fr(2)];
-    // const newContext = context.createNestedContractCallContext(newAddress, newCalldata);
+    const context = initContext();
+    context.machineState.pc = 20;
+
+    const newAddress = AztecAddress.random();
+    const newCalldata = [new Fr(1), new Fr(2)];
+    const newContext = context.createNestedContractCallContext(newAddress, newCalldata);
+
+    expect(newContext.environment).toEqual(
+      allSameExcept(context.environment, {
+        address: newAddress,
+        storageAddress: newAddress,
+        calldata: newCalldata,
+        isStaticCall: false,
+      }),
+    );
+    expect(newContext.machineState).toEqual(
+      allSameExcept(context.machineState, {
+        pc: 0,
+      }),
+    );
+    // FIXME: I can't get this to work.
+    // expect(newContext.worldState).toEqual(context.worldState.fork());
   });
 
   it('New static call should fork context correctly', () => {
-    // const context = initContext();
-    // const newAddress = AztecAddress.random();
-    // const newCalldata = [new Fr(1), new Fr(2)];
-    // const newContext = context.createNestedContractStaticCallContext(newAddress, newCalldata);
+    const context = initContext();
+    context.machineState.pc = 20;
+
+    const newAddress = AztecAddress.random();
+    const newCalldata = [new Fr(1), new Fr(2)];
+    const newContext = context.createNestedContractStaticCallContext(newAddress, newCalldata);
+
+    expect(newContext.environment).toEqual(
+      allSameExcept(context.environment, {
+        address: newAddress,
+        storageAddress: newAddress,
+        calldata: newCalldata,
+        isStaticCall: true,
+      }),
+    );
+    expect(newContext.machineState).toEqual(
+      allSameExcept(context.machineState, {
+        pc: 0,
+      }),
+    );
+    // FIXME: I can't get this to work.
+    // expect(newContext.worldState).toEqual(context.worldState.fork());
   });
 });
diff --git a/yarn-project/simulator/src/avm/avm_execution_environment.test.ts b/yarn-project/simulator/src/avm/avm_execution_environment.test.ts
index 27043eb3660..e2104cbad59 100644
--- a/yarn-project/simulator/src/avm/avm_execution_environment.test.ts
+++ b/yarn-project/simulator/src/avm/avm_execution_environment.test.ts
@@ -1,6 +1,6 @@
 import { Fr } from '@aztec/foundation/fields';
 
-import { initExecutionEnvironment } from './fixtures/index.js';
+import { allSameExcept, initExecutionEnvironment } from './fixtures/index.js';
 
 describe('Execution Environment', () => {
   const newAddress = new Fr(123456n);
@@ -10,46 +10,39 @@ describe('Execution Environment', () => {
     const executionEnvironment = initExecutionEnvironment();
     const newExecutionEnvironment = executionEnvironment.deriveEnvironmentForNestedCall(newAddress, calldata);
 
-    allTheSameExcept(executionEnvironment, newExecutionEnvironment, {
-      address: newAddress,
-      storageAddress: newAddress,
-      calldata,
-    });
+    expect(newExecutionEnvironment).toEqual(
+      allSameExcept(executionEnvironment, {
+        address: newAddress,
+        storageAddress: newAddress,
+        calldata,
+      }),
+    );
   });
 
   it('New delegate call should fork execution environment correctly', () => {
     const executionEnvironment = initExecutionEnvironment();
     const newExecutionEnvironment = executionEnvironment.newDelegateCall(newAddress, calldata);
 
-    allTheSameExcept(executionEnvironment, newExecutionEnvironment, {
-      address: newAddress,
-      isDelegateCall: true,
-      calldata,
-    });
+    expect(newExecutionEnvironment).toEqual(
+      allSameExcept(executionEnvironment, {
+        address: newAddress,
+        isDelegateCall: true,
+        calldata,
+      }),
+    );
   });
 
   it('New static call call should fork execution environment correctly', () => {
     const executionEnvironment = initExecutionEnvironment();
     const newExecutionEnvironment = executionEnvironment.deriveEnvironmentForNestedStaticCall(newAddress, calldata);
 
-    allTheSameExcept(executionEnvironment, newExecutionEnvironment, {
-      address: newAddress,
-      storageAddress: newAddress,
-      isStaticCall: true,
-      calldata,
-    });
+    expect(newExecutionEnvironment).toEqual(
+      allSameExcept(executionEnvironment, {
+        address: newAddress,
+        storageAddress: newAddress,
+        isStaticCall: true,
+        calldata,
+      }),
+    );
   });
 });
-
-/**
- * Check all properties of one object are the same, except for the specified differentProperties
- */
-function allTheSameExcept(referenceObject: any, comparingObject: any, differentProperties: Record<string, any>): void {
-  for (const key in referenceObject) {
-    if (Object.keys(differentProperties).includes(key)) {
-      expect(comparingObject[key]).toEqual(differentProperties[key]);
-    } else {
-      expect(comparingObject[key]).toEqual(referenceObject[key]);
-    }
-  }
-}
diff --git a/yarn-project/simulator/src/avm/avm_memory_types.test.ts b/yarn-project/simulator/src/avm/avm_memory_types.test.ts
index 6df75930fe1..c5701c54d93 100644
--- a/yarn-project/simulator/src/avm/avm_memory_types.test.ts
+++ b/yarn-project/simulator/src/avm/avm_memory_types.test.ts
@@ -1,22 +1,190 @@
-import { Field, Uint8 } from './avm_memory_types.js';
+import { Field, TaggedMemory, Uint8, Uint16, Uint32, Uint64, Uint128 } from './avm_memory_types.js';
 
-// TODO: complete
-describe('Uint8', () => {
-  it('Unsigned 8 max value', () => {
-    expect(new Uint8(255).toBigInt()).toEqual(255n);
+describe('TaggedMemory', () => {
+  it('Elements should be undefined after construction', () => {
+    const mem = new TaggedMemory();
+    expect(mem.get(10)).toBe(undefined);
   });
 
-  it('Unsigned 8 bit add', () => {
-    expect(new Uint8(50).add(new Uint8(20))).toEqual(new Uint8(70));
+  it(`Should set and get integral types`, () => {
+    const mem = new TaggedMemory();
+    mem.set(10, new Uint8(5));
+    expect(mem.get(10)).toStrictEqual(new Uint8(5));
   });
 
-  it('Unsigned 8 bit add wraps', () => {
-    expect(new Uint8(200).add(new Uint8(100))).toEqual(new Uint8(44));
+  it(`Should set and get field elements`, () => {
+    const mem = new TaggedMemory();
+    mem.set(10, new Field(5));
+    expect(mem.get(10)).toStrictEqual(new Field(5));
+  });
+
+  it(`Should getSlice beyond current size`, () => {
+    const mem = new TaggedMemory();
+    const val = [new Field(5), new Field(6)];
+
+    mem.setSlice(10, val);
+
+    expect(mem.getSlice(10, /*size=*/ 4)).toEqual([...val, undefined, undefined]);
+  });
+
+  it(`Should set and get slices`, () => {
+    const mem = new TaggedMemory();
+    const val = [new Field(5), new Field(6)];
+
+    mem.setSlice(10, val);
+
+    expect(mem.getSlice(10, /*size=*/ 2)).toStrictEqual(val);
+  });
+});
+
+type IntegralClass = typeof Uint8 | typeof Uint16 | typeof Uint32 | typeof Uint64 | typeof Uint128;
+describe.each([Uint8, Uint16, Uint32, Uint64, Uint128])('Integral Types', (clsValue: IntegralClass) => {
+  it(`Should construct a new ${clsValue.name} from a number`, () => {
+    const x = new clsValue(5);
+    expect(x.toBigInt()).toStrictEqual(5n);
+  });
+
+  it(`Should construct a new ${clsValue.name} from a bigint`, () => {
+    const x = new clsValue(5n);
+    expect(x.toBigInt()).toStrictEqual(5n);
+  });
+
+  it(`Should build a new ${clsValue.name}`, () => {
+    const x = new clsValue(5);
+    const newX = x.build(10n);
+    expect(newX).toStrictEqual(new clsValue(10n));
+  });
+
+  it(`Should add two ${clsValue.name} correctly`, () => {
+    const a = new clsValue(5);
+    const b = new clsValue(10);
+    const result = a.add(b);
+    expect(result).toStrictEqual(new clsValue(15n));
+  });
+
+  it(`Should subtract two ${clsValue.name} correctly`, () => {
+    const a = new clsValue(10);
+    const b = new clsValue(5);
+    const result = a.sub(b);
+    expect(result).toStrictEqual(new clsValue(5n));
+  });
+
+  it(`Should multiply two ${clsValue.name} correctly`, () => {
+    const a = new clsValue(5);
+    const b = new clsValue(10);
+    const result = a.mul(b);
+    expect(result).toStrictEqual(new clsValue(50n));
+  });
+
+  it(`Should divide two ${clsValue.name} correctly`, () => {
+    const a = new clsValue(10);
+    const b = new clsValue(5);
+    const result = a.div(b);
+    expect(result).toStrictEqual(new clsValue(2n));
+  });
+
+  it('Should shift right ${clsValue.name} correctly', () => {
+    const uintA = new clsValue(10);
+    const result = uintA.shr(new clsValue(1n));
+    expect(result).toEqual(new clsValue(5n));
+  });
+
+  it('Should shift left ${clsValue.name} correctly', () => {
+    const uintA = new clsValue(10);
+    const result = uintA.shl(new clsValue(1n));
+    expect(result).toEqual(new clsValue(20n));
+  });
+
+  it('Should and two ${clsValue.name} correctly', () => {
+    const uintA = new clsValue(10);
+    const uintB = new clsValue(5);
+    const result = uintA.and(uintB);
+    expect(result).toEqual(new clsValue(0n));
+  });
+
+  it('Should or two ${clsValue.name} correctly', () => {
+    const uintA = new clsValue(10);
+    const uintB = new clsValue(5);
+    const result = uintA.or(uintB);
+    expect(result).toEqual(new clsValue(15n));
+  });
+
+  it('Should xor two ${clsValue.name} correctly', () => {
+    const uintA = new clsValue(10);
+    const uintB = new clsValue(5);
+    const result = uintA.xor(uintB);
+    expect(result).toEqual(new clsValue(15n));
+  });
+
+  it(`Should check equality of two ${clsValue.name} correctly`, () => {
+    const a = new clsValue(5);
+    const b = new clsValue(5);
+    const c = new clsValue(10);
+    expect(a.equals(b)).toBe(true);
+    expect(a.equals(c)).toBe(false);
+  });
+
+  it(`Should check if one ${clsValue.name} is less than another correctly`, () => {
+    const a = new clsValue(5);
+    const b = new clsValue(10);
+    expect(a.lt(b)).toBe(true);
+    expect(b.lt(a)).toBe(false);
   });
 });
 
 describe('Field', () => {
-  it('Add correctly without wrapping', () => {
-    expect(new Field(27).add(new Field(48))).toEqual(new Field(75));
+  it(`Should build a new Field`, () => {
+    const field = new Field(5);
+    const newField = field.build(10n);
+    expect(newField.toBigInt()).toStrictEqual(10n);
+  });
+
+  it(`Should add two Fields correctly`, () => {
+    const field1 = new Field(5);
+    const field2 = new Field(10);
+    const result = field1.add(field2);
+    expect(result).toStrictEqual(new Field(15n));
+  });
+
+  it(`Should subtract two Fields correctly`, () => {
+    const field1 = new Field(10);
+    const field2 = new Field(5);
+    const result = field1.sub(field2);
+    expect(result).toStrictEqual(new Field(5n));
+  });
+
+  it(`Should multiply two Fields correctly`, () => {
+    const field1 = new Field(5);
+    const field2 = new Field(10);
+    const result = field1.mul(field2);
+    expect(result).toStrictEqual(new Field(50n));
+  });
+
+  // FIXME: field division is wrong
+  it.skip(`Should divide two Fields correctly`, () => {
+    const field1 = new Field(10);
+    const field2 = new Field(5);
+    const result = field1.div(field2);
+    expect(result).toStrictEqual(new Field(2n));
+  });
+
+  it(`Should check equality of two Fields correctly`, () => {
+    const field1 = new Field(5);
+    const field2 = new Field(5);
+    const field3 = new Field(10);
+    expect(field1.equals(field2)).toBe(true);
+    expect(field1.equals(field3)).toBe(false);
+  });
+
+  it(`Should check if one Field is less than another correctly`, () => {
+    const field1 = new Field(5);
+    const field2 = new Field(10);
+    expect(field1.lt(field2)).toBe(true);
+    expect(field2.lt(field1)).toBe(false);
+  });
+
+  it(`Should convert Field to BigInt correctly`, () => {
+    const field = new Field(5);
+    expect(field.toBigInt()).toStrictEqual(5n);
   });
 });
diff --git a/yarn-project/simulator/src/avm/avm_memory_types.ts b/yarn-project/simulator/src/avm/avm_memory_types.ts
index e620263f059..12df18223c1 100644
--- a/yarn-project/simulator/src/avm/avm_memory_types.ts
+++ b/yarn-project/simulator/src/avm/avm_memory_types.ts
@@ -223,15 +223,16 @@ export enum TypeTag {
 // TODO: Consider automatic conversion when getting undefined values.
 export class TaggedMemory {
   // FIXME: memory should be 2^32, but TS doesn't allow for arrays that big.
-  static readonly MAX_MEMORY_SIZE = Number(1n << 31n); // 1n << 32n
+  static readonly MAX_MEMORY_SIZE = Number((1n << 32n) - 2n);
   private _mem: MemoryValue[];
 
   constructor() {
-    // Initialize memory size, but leave all entries undefined.
-    this._mem = new Array(TaggedMemory.MAX_MEMORY_SIZE);
+    // We do not initialize memory size here because otherwise tests blow up when diffing.
+    this._mem = [];
   }
 
   public get(offset: number): MemoryValue {
+    assert(offset < TaggedMemory.MAX_MEMORY_SIZE);
     return this.getAs<MemoryValue>(offset);
   }
 
@@ -243,16 +244,19 @@ export class TaggedMemory {
 
   public getSlice(offset: number, size: number): MemoryValue[] {
     assert(offset < TaggedMemory.MAX_MEMORY_SIZE);
+    assert(offset + size < TaggedMemory.MAX_MEMORY_SIZE);
     return this._mem.slice(offset, offset + size);
   }
 
   public getSliceAs<T>(offset: number, size: number): T[] {
     assert(offset < TaggedMemory.MAX_MEMORY_SIZE);
+    assert(offset + size < TaggedMemory.MAX_MEMORY_SIZE);
     return this._mem.slice(offset, offset + size) as T[];
   }
 
   public getSliceTags(offset: number, size: number): TypeTag[] {
     assert(offset < TaggedMemory.MAX_MEMORY_SIZE);
+    assert(offset + size < TaggedMemory.MAX_MEMORY_SIZE);
     return this._mem.slice(offset, offset + size).map(TaggedMemory.getTag);
   }
 
@@ -263,6 +267,11 @@ export class TaggedMemory {
 
   public setSlice(offset: number, vs: MemoryValue[]) {
     assert(offset < TaggedMemory.MAX_MEMORY_SIZE);
+    assert(offset + vs.length < TaggedMemory.MAX_MEMORY_SIZE);
+    // We may need to extend the memory size, otherwise splice doesn't insert.
+    if (offset + vs.length > this._mem.length) {
+      this._mem.length = offset + vs.length;
+    }
     this._mem.splice(offset, vs.length, ...vs);
   }
 
diff --git a/yarn-project/simulator/src/avm/fixtures/index.ts b/yarn-project/simulator/src/avm/fixtures/index.ts
index bdbf5bed4bc..565622a40f3 100644
--- a/yarn-project/simulator/src/avm/fixtures/index.ts
+++ b/yarn-project/simulator/src/avm/fixtures/index.ts
@@ -4,6 +4,7 @@ import { EthAddress } from '@aztec/foundation/eth-address';
 import { Fr } from '@aztec/foundation/fields';
 
 import { mock } from 'jest-mock-extended';
+import merge from 'lodash.merge';
 
 import { CommitmentsDB, PublicContractsDB, PublicStateDB } from '../../index.js';
 import { AvmContext } from '../avm_context.js';
@@ -76,3 +77,10 @@ export function initMachineState(overrides?: Partial<AvmMachineState>): AvmMachi
     daGasLeft: overrides?.daGasLeft ?? 0,
   });
 }
+
+/**
+ * Create a new object with all the same properties as the original, except for the ones in the overrides object.
+ */
+export function allSameExcept(original: any, overrides: any): any {
+  return merge({}, original, overrides);
+}
diff --git a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
index a66201a9808..1475ef1a7c4 100644
--- a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
+++ b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
@@ -201,9 +201,10 @@ describe('Arithmetic Instructions', () => {
       expect(inst.serialize()).toEqual(buf);
     });
 
-    it('Should perform field division', async () => {
-      const a = new Field(2n);
-      const b = new Field(3n);
+    // FIXME: field division is wrong
+    it.skip('Should perform field division', async () => {
+      const a = new Field(10n);
+      const b = new Field(5n);
 
       context.machineState.memory.set(0, a);
       context.machineState.memory.set(1, b);
@@ -217,8 +218,7 @@ describe('Arithmetic Instructions', () => {
       ).execute(context);
 
       const actual = context.machineState.memory.get(2);
-      const recovered = actual.mul(b);
-      expect(recovered).toEqual(a);
+      expect(actual).toEqual(new Field(2));
     });
   });
 });
diff --git a/yarn-project/simulator/src/avm/opcodes/environment_getters.test.ts b/yarn-project/simulator/src/avm/opcodes/environment_getters.test.ts
index 0af20744a53..be9505d4e19 100644
--- a/yarn-project/simulator/src/avm/opcodes/environment_getters.test.ts
+++ b/yarn-project/simulator/src/avm/opcodes/environment_getters.test.ts
@@ -16,253 +16,77 @@ import {
   Version,
 } from './environment_getters.js';
 
-describe('Environment getters instructions', () => {
-  type EnvInstruction = Portal | FeePerL1Gas | FeePerL2Gas | FeePerDAGas | Origin | Sender | StorageAddress | Address;
-  const envGetterTest = async (key: string, value: Fr, instruction: EnvInstruction) => {
+type EnvInstruction =
+  | typeof Portal
+  | typeof FeePerL1Gas
+  | typeof FeePerL2Gas
+  | typeof FeePerDAGas
+  | typeof Origin
+  | typeof Sender
+  | typeof StorageAddress
+  | typeof Address;
+describe.each([
+  [Portal, 'portal'],
+  [FeePerL1Gas, 'feePerL1Gas'],
+  [FeePerL2Gas, 'feePerL2Gas'],
+  [FeePerDAGas, 'feePerDaGas'],
+  [Origin, 'origin'],
+  [Sender, 'sender'],
+  [StorageAddress, 'storageAddress'],
+  [Address, 'address'],
+])('Environment getters instructions', (clsValue: EnvInstruction, key: string) => {
+  it(`${clsValue.name} should (de)serialize correctly`, () => {
+    const buf = Buffer.from([
+      clsValue.opcode, // opcode
+      0x01, // indirect
+      ...Buffer.from('12345678', 'hex'), // dstOffset
+    ]);
+    const inst = new clsValue(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
+
+    expect(clsValue.deserialize(buf)).toEqual(inst);
+    expect(inst.serialize()).toEqual(buf);
+  });
+
+  it(`${clsValue.name} should read '${key}' correctly`, async () => {
+    const value = new Fr(123456n);
+    const instruction = new clsValue(/*indirect=*/ 0, /*dstOffset=*/ 0);
     const context = initContext({ env: initExecutionEnvironment({ [key]: value }) });
 
     await instruction.execute(context);
+
     const actual = context.machineState.memory.get(0).toFr();
     expect(actual).toEqual(value);
-  };
-
-  describe('Address', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        Address.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new Address(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(Address.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read address correctly', async () => {
-      const address = new Fr(123456n);
-      await envGetterTest('address', address, new Address(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('StorageAddress', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        StorageAddress.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new StorageAddress(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(StorageAddress.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read storage address correctly', async () => {
-      const address = new Fr(123456n);
-      await envGetterTest('storageAddress', address, new StorageAddress(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('Portal', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        Portal.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new Portal(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(Portal.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read Portal correctly', async () => {
-      const portal = new Fr(123456n);
-      await envGetterTest('portal', portal, new Portal(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('FeePerL1Gas', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        FeePerL1Gas.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new FeePerL1Gas(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(FeePerL1Gas.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read FeePerL1Gas correctly', async () => {
-      const feePerL1Gas = new Fr(123456n);
-      await envGetterTest('feePerL1Gas', feePerL1Gas, new FeePerL1Gas(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
   });
+});
 
-  describe('FeePerL2Gas', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        FeePerL2Gas.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new FeePerL2Gas(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(FeePerL2Gas.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read FeePerL2Gas correctly', async () => {
-      const feePerL2Gas = new Fr(123456n);
-      await envGetterTest('feePerL2Gas', feePerL2Gas, new FeePerL2Gas(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('FeePerDAGas', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        FeePerDAGas.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new FeePerDAGas(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(FeePerDAGas.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read FeePerDAGas correctly', async () => {
-      const feePerDaGas = new Fr(123456n);
-      await envGetterTest('feePerDaGas', feePerDaGas, new FeePerDAGas(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('Origin', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        Origin.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new Origin(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(Origin.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read Origin correctly', async () => {
-      const origin = new Fr(123456n);
-      await envGetterTest('origin', origin, new Origin(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
-  });
-
-  describe('Sender', () => {
-    it('Should (de)serialize correctly', () => {
-      const buf = Buffer.from([
-        Sender.opcode, // opcode
-        0x01, // indirect
-        ...Buffer.from('12345678', 'hex'), // dstOffset
-      ]);
-      const inst = new Sender(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-      expect(Sender.deserialize(buf)).toEqual(inst);
-      expect(inst.serialize()).toEqual(buf);
-    });
-
-    it('Should read Sender correctly', async () => {
-      const sender = new Fr(123456n);
-      await envGetterTest('sender', sender, new Sender(/*indirect=*/ 0, /*dstOffset=*/ 0));
-    });
+type GlobalsInstruction = typeof ChainId | typeof Version | typeof BlockNumber | typeof Timestamp;
+describe.each([
+  [ChainId, 'chainId'],
+  [Version, 'version'],
+  [BlockNumber, 'blockNumber'],
+  [Timestamp, 'timestamp'],
+])('Global Variables', (clsValue: GlobalsInstruction, key: string) => {
+  it(`${clsValue.name} should (de)serialize correctly`, () => {
+    const buf = Buffer.from([
+      clsValue.opcode, // opcode
+      0x01, // indirect
+      ...Buffer.from('12345678', 'hex'), // dstOffset
+    ]);
+    const inst = new clsValue(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
+
+    expect(clsValue.deserialize(buf)).toEqual(inst);
+    expect(inst.serialize()).toEqual(buf);
   });
 
-  describe('Global Variables', () => {
-    type GlobalsInstruction = ChainId | Version | BlockNumber | Timestamp;
-    const readGlobalVariableTest = async (key: string, value: Fr, instruction: GlobalsInstruction) => {
-      const globals = initGlobalVariables({ [key]: value });
-      const context = initContext({ env: initExecutionEnvironment({ globals }) });
-
-      await instruction.execute(context);
-      const actual = context.machineState.memory.get(0).toFr();
-      expect(actual).toEqual(value);
-    };
-
-    describe('chainId', () => {
-      it('Should (de)serialize correctly', () => {
-        const buf = Buffer.from([
-          ChainId.opcode, // opcode
-          0x01, // indirect
-          ...Buffer.from('12345678', 'hex'), // dstOffset
-        ]);
-        const inst = new ChainId(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-        expect(ChainId.deserialize(buf)).toEqual(inst);
-        expect(inst.serialize()).toEqual(buf);
-      });
+  it(`${clsValue.name} should read '${key}' correctly`, async () => {
+    const value = new Fr(123456n);
+    const instruction = new clsValue(/*indirect=*/ 0, /*dstOffset=*/ 0);
+    const globals = initGlobalVariables({ [key]: value });
+    const context = initContext({ env: initExecutionEnvironment({ globals }) });
 
-      it('Should read chainId', async () => {
-        const chainId = new Fr(123456n);
-        await readGlobalVariableTest('chainId', chainId, new ChainId(/*indirect=*/ 0, /*dstOffset=*/ 0));
-      });
-    });
-
-    describe('version', () => {
-      it('Should (de)serialize correctly', () => {
-        const buf = Buffer.from([
-          Version.opcode, // opcode
-          0x01, // indirect
-          ...Buffer.from('12345678', 'hex'), // dstOffset
-        ]);
-        const inst = new Version(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-        expect(Version.deserialize(buf)).toEqual(inst);
-        expect(inst.serialize()).toEqual(buf);
-      });
-
-      it('Should read version', async () => {
-        const version = new Fr(123456n);
-        await readGlobalVariableTest('version', version, new Version(/*indirect=*/ 0, /*dstOffset=*/ 0));
-      });
-    });
-
-    describe('block', () => {
-      it('Should (de)serialize correctly', () => {
-        const buf = Buffer.from([
-          BlockNumber.opcode, // opcode
-          0x01, // indirect
-          ...Buffer.from('12345678', 'hex'), // dstOffset
-        ]);
-        const inst = new BlockNumber(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-        expect(BlockNumber.deserialize(buf)).toEqual(inst);
-        expect(inst.serialize()).toEqual(buf);
-      });
-
-      it('Should read block number', async () => {
-        const blockNumber = new Fr(123456n);
-        await readGlobalVariableTest('blockNumber', blockNumber, new BlockNumber(/*indirect=*/ 0, /*dstOffset=*/ 0));
-      });
-    });
-
-    describe('timestamp', () => {
-      it('Should (de)serialize correctly', () => {
-        const buf = Buffer.from([
-          Timestamp.opcode, // opcode
-          0x01, // indirect
-          ...Buffer.from('12345678', 'hex'), // dstOffset
-        ]);
-        const inst = new Timestamp(/*indirect=*/ 0x01, /*dstOffset=*/ 0x12345678);
-
-        expect(Timestamp.deserialize(buf)).toEqual(inst);
-        expect(inst.serialize()).toEqual(buf);
-      });
+    await instruction.execute(context);
 
-      it('Should read timestamp', async () => {
-        const timestamp = new Fr(123456n);
-        await readGlobalVariableTest('timestamp', timestamp, new Timestamp(/*indirect=*/ 0, /*dstOffset=*/ 0));
-      });
-    });
+    const actual = context.machineState.memory.get(0).toFr();
+    expect(actual).toEqual(value);
   });
 });
diff --git a/yarn-project/yarn.lock b/yarn-project/yarn.lock
index 3555e8cfda0..dbd0d37b131 100644
--- a/yarn-project/yarn.lock
+++ b/yarn-project/yarn.lock
@@ -836,11 +836,13 @@ __metadata:
     "@noir-lang/acvm_js": "portal:../../noir/packages/acvm_js"
     "@types/jest": ^29.5.0
     "@types/levelup": ^5.1.3
+    "@types/lodash.merge": ^4.6.9
     "@types/memdown": ^3.0.2
     "@types/node": ^18.7.23
     jest: ^29.5.0
     jest-mock-extended: ^3.0.4
     levelup: ^5.1.1
+    lodash.merge: ^4.6.2
     memdown: ^6.1.1
     ts-jest: ^29.1.0
     ts-node: ^10.9.1
@@ -3434,6 +3436,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/lodash.merge@npm:^4.6.9":
+  version: 4.6.9
+  resolution: "@types/lodash.merge@npm:4.6.9"
+  dependencies:
+    "@types/lodash": "*"
+  checksum: d0dd6654547c9d8d905184d14aa5c2a37a1ed1c3204f5ab20b7d591a05f34859ef09d3b72c065e94ca1989abf9109eb8230f67c4d64a5768b1d65b9ed8baf8e7
+  languageName: node
+  linkType: hard
+
 "@types/lodash.omit@npm:^4.5.7":
   version: 4.5.9
   resolution: "@types/lodash.omit@npm:4.5.9"

From 824fb804f60ddf0a48eda51c852bf10d7dea83e3 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:30:18 +0000
Subject: [PATCH 03/12] journal compare

---
 .../simulator/src/avm/avm_context.test.ts         | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index f54fe99a358..3eab56099d3 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -1,6 +1,7 @@
 import { AztecAddress, Fr } from '@aztec/circuits.js';
 
 import { allSameExcept, initContext } from './fixtures/index.js';
+import { AvmWorldStateJournal } from './journal/journal.js';
 
 describe('Avm Context', () => {
   it('New call should fork context correctly', () => {
@@ -24,10 +25,20 @@ describe('Avm Context', () => {
         pc: 0,
       }),
     );
-    // FIXME: I can't get this to work.
-    // expect(newContext.worldState).toEqual(context.worldState.fork());
+
+    compareJournal(newContext.worldState, context.worldState);
   });
 
+  function compareJournal(actual: AvmWorldStateJournal, expected: AvmWorldStateJournal) {
+    const removeParentReference = (journal: AvmWorldStateJournal) => {
+      const j = JSON.parse(JSON.stringify(journal));
+      delete j.parentJournal;
+      return j;
+    }
+
+    expect(removeParentReference(actual)).toEqual(removeParentReference(expected));
+  }
+
   it('New static call should fork context correctly', () => {
     const context = initContext();
     context.machineState.pc = 20;

From 781d2fdcb719c22e43182db0b73e1b8589e1ac59 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:33:04 +0000
Subject: [PATCH 04/12] add fork

---
 yarn-project/simulator/src/avm/avm_context.test.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index 3eab56099d3..6a9f332715e 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -26,7 +26,7 @@ describe('Avm Context', () => {
       }),
     );
 
-    compareJournal(newContext.worldState, context.worldState);
+    compareJournal(newContext.worldState, context.worldState.fork());
   });
 
   function compareJournal(actual: AvmWorldStateJournal, expected: AvmWorldStateJournal) {

From 8e7deea6b8525ca48c6e0e390553d50ca12d8973 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:48:07 +0000
Subject: [PATCH 05/12] strinfigy does the job

---
 .../simulator/src/avm/avm_context.test.ts         | 15 ++++-----------
 .../simulator/src/avm/opcodes/arithmetic.test.ts  |  2 +-
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index 6a9f332715e..4201cb9bf3f 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -8,6 +8,8 @@ describe('Avm Context', () => {
     const context = initContext();
     context.machineState.pc = 20;
 
+    
+
     const newAddress = AztecAddress.random();
     const newCalldata = [new Fr(1), new Fr(2)];
     const newContext = context.createNestedContractCallContext(newAddress, newCalldata);
@@ -26,19 +28,10 @@ describe('Avm Context', () => {
       }),
     );
 
-    compareJournal(newContext.worldState, context.worldState.fork());
+    // We stringify to remove circular references (parentJournal)
+    expect(JSON.stringify(newContext.worldState)).toEqual(JSON.stringify(context.worldState.fork()));
   });
 
-  function compareJournal(actual: AvmWorldStateJournal, expected: AvmWorldStateJournal) {
-    const removeParentReference = (journal: AvmWorldStateJournal) => {
-      const j = JSON.parse(JSON.stringify(journal));
-      delete j.parentJournal;
-      return j;
-    }
-
-    expect(removeParentReference(actual)).toEqual(removeParentReference(expected));
-  }
-
   it('New static call should fork context correctly', () => {
     const context = initContext();
     context.machineState.pc = 20;
diff --git a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
index 1475ef1a7c4..42680477fc3 100644
--- a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
+++ b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
@@ -202,7 +202,7 @@ describe('Arithmetic Instructions', () => {
     });
 
     // FIXME: field division is wrong
-    it.skip('Should perform field division', async () => {
+    it('Should perform field division', async () => {
       const a = new Field(10n);
       const b = new Field(5n);
 

From 97bacf941983661ee3d7c804c09c43d9c8e9d849 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:54:48 +0000
Subject: [PATCH 06/12] fix: field division

---
 yarn-project/foundation/src/fields/fields.ts              | 4 ++--
 yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts | 1 -
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/yarn-project/foundation/src/fields/fields.ts b/yarn-project/foundation/src/fields/fields.ts
index 0aebb8fa3cc..b4dc1229d5f 100644
--- a/yarn-project/foundation/src/fields/fields.ts
+++ b/yarn-project/foundation/src/fields/fields.ts
@@ -298,8 +298,8 @@ function modInverse(b: bigint) {
   if (gcd != 1n) {
     throw Error('Inverse does not exist');
   }
-  // Add modulus to ensure positive
-  return new Fr(x + Fr.MODULUS);
+  // Add modulus if -ve to ensure positive
+  return new Fr(x > 0 ? x : x + Fr.MODULUS);
 }
 
 /**
diff --git a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
index 42680477fc3..e08fe4bcb8e 100644
--- a/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
+++ b/yarn-project/simulator/src/avm/opcodes/arithmetic.test.ts
@@ -201,7 +201,6 @@ describe('Arithmetic Instructions', () => {
       expect(inst.serialize()).toEqual(buf);
     });
 
-    // FIXME: field division is wrong
     it('Should perform field division', async () => {
       const a = new Field(10n);
       const b = new Field(5n);

From 600b3f16697a4c6d1132908d9779a5066ff2ba38 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 16:56:27 +0000
Subject: [PATCH 07/12] fmt

---
 yarn-project/simulator/src/avm/avm_context.test.ts | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index 4201cb9bf3f..50323b05f0e 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -1,15 +1,12 @@
 import { AztecAddress, Fr } from '@aztec/circuits.js';
 
 import { allSameExcept, initContext } from './fixtures/index.js';
-import { AvmWorldStateJournal } from './journal/journal.js';
 
 describe('Avm Context', () => {
   it('New call should fork context correctly', () => {
     const context = initContext();
     context.machineState.pc = 20;
 
-    
-
     const newAddress = AztecAddress.random();
     const newCalldata = [new Fr(1), new Fr(2)];
     const newContext = context.createNestedContractCallContext(newAddress, newCalldata);

From e4929b821dd5b3252434e4f8cd28e6d1c9ab180f Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 17:03:31 +0000
Subject: [PATCH 08/12] another context

---
 yarn-project/simulator/src/avm/avm_context.test.ts | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/yarn-project/simulator/src/avm/avm_context.test.ts b/yarn-project/simulator/src/avm/avm_context.test.ts
index 50323b05f0e..240de5eb14f 100644
--- a/yarn-project/simulator/src/avm/avm_context.test.ts
+++ b/yarn-project/simulator/src/avm/avm_context.test.ts
@@ -50,7 +50,8 @@ describe('Avm Context', () => {
         pc: 0,
       }),
     );
-    // FIXME: I can't get this to work.
-    // expect(newContext.worldState).toEqual(context.worldState.fork());
+
+    // We stringify to remove circular references (parentJournal)
+    expect(JSON.stringify(newContext.worldState)).toEqual(JSON.stringify(context.worldState.fork()));
   });
 });

From 09ad78a93a8f5e9919b1590276881122f0b31c67 Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 17:06:27 +0000
Subject: [PATCH 09/12] fix: one more field division

---
 yarn-project/simulator/src/avm/avm_memory_types.test.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/yarn-project/simulator/src/avm/avm_memory_types.test.ts b/yarn-project/simulator/src/avm/avm_memory_types.test.ts
index c5701c54d93..9aeccaa73b9 100644
--- a/yarn-project/simulator/src/avm/avm_memory_types.test.ts
+++ b/yarn-project/simulator/src/avm/avm_memory_types.test.ts
@@ -160,8 +160,7 @@ describe('Field', () => {
     expect(result).toStrictEqual(new Field(50n));
   });
 
-  // FIXME: field division is wrong
-  it.skip(`Should divide two Fields correctly`, () => {
+  it(`Should divide two Fields correctly`, () => {
     const field1 = new Field(10);
     const field2 = new Field(5);
     const result = field1.div(field2);

From a0fb6a9e4339260d602704de4de2cb1fb5b49b6c Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 17:35:57 +0000
Subject: [PATCH 10/12] feat: field division tests

---
 .../foundation/src/fields/fields.test.ts      | 122 +++++++++++++++++-
 1 file changed, 121 insertions(+), 1 deletion(-)

diff --git a/yarn-project/foundation/src/fields/fields.test.ts b/yarn-project/foundation/src/fields/fields.test.ts
index 02f08f0e319..f8ad991a245 100644
--- a/yarn-project/foundation/src/fields/fields.test.ts
+++ b/yarn-project/foundation/src/fields/fields.test.ts
@@ -1,4 +1,4 @@
-import { GrumpkinScalar } from './fields.js';
+import { GrumpkinScalar, Fr } from './fields.js';
 
 describe('GrumpkinScalar Serialization', () => {
   // Test case for GrumpkinScalar.fromHighLow
@@ -53,3 +53,123 @@ describe('GrumpkinScalar Serialization', () => {
     expect(deserialized).toEqual(original);
   });
 });
+
+describe("Bn254 arithmetic", () => {
+  describe("Addition", () => {
+    it("Low Boundary", () => {
+      // 0 + -1 = -1
+      const a = Fr.ZERO;
+      const b = new Fr(Fr.MODULUS - 1n);
+      const expected = new Fr(Fr.MODULUS - 1n);
+
+      const actual = a.add(b);
+      expect(actual).toEqual(expected);
+    })
+
+    it("High Boundary", () => {
+      // -1 + 1 = 0
+      const a = new Fr(Fr.MODULUS - 1n);
+      const b = new Fr(1);
+      const expected = Fr.ZERO;
+
+      const actual = a.add(b);
+      expect(actual).toEqual(expected);
+    });
+
+    it("Performs addition correctly", () => {
+      const a = new Fr(2);
+      const b = new Fr(3);
+      const expected = new Fr(5);
+
+      const actual = a.add(b);
+      expect(actual).toEqual(expected);
+    })
+  })
+
+  describe("Subtraction", () => {
+    it("Low Boundary", () => {
+      // 0 - 1 = -1
+      const a = new Fr(0);
+      const b = new Fr(1);
+      const expected = new Fr(Fr.MODULUS - 1n);
+
+      const actual = a.sub(b);
+      expect(actual).toEqual(expected);
+    })
+
+    it("High Bonudary", () => {
+      // -1 - (-1) = 0
+      const a = new Fr(Fr.MODULUS - 1n);
+      const b = new Fr(Fr.MODULUS - 1n);
+
+      const actual = a.sub(b);
+      expect(actual).toEqual(Fr.ZERO);
+    })
+
+    it("Performs subtraction correctly", () => {
+      const a = new Fr(10);
+      const b = new Fr(5);
+      const expected = new Fr(5);
+
+      const actual = a.sub(b);
+      expect(actual).toEqual(expected);
+    });
+  })
+
+  describe("Multiplication", () => {
+    it("Identity", () => {
+      const a = new Fr(Fr.MODULUS - 1n);
+      const b = new Fr(1);
+      const expected = new Fr(Fr.MODULUS - 1n);
+
+      const actual = a.mul(b);
+      expect(actual).toEqual(expected);
+    });
+
+    it("Performs multiplication correctly", () => {
+      const a = new Fr(2);
+      const b = new Fr(3);
+      const expected = new Fr(6);
+
+      const actual = a.mul(b);
+      expect(actual).toEqual(expected);
+    });
+
+    it("High Boundary", () => {
+      const a = new Fr(Fr.MODULUS - 1n);
+      const b = new Fr(Fr.MODULUS / 2n);
+      const expected = new Fr(10944121435919637611123202872628637544274182200208017171849102093287904247809n);
+
+      const actual = a.mul(b);
+      expect(actual).toEqual(expected);
+    });
+  })
+
+
+  describe("Division", () => {
+    it("Should succeed when mod inverse is -ve", () => {
+      const a = new Fr(2);
+      const b = new Fr(3);
+
+      const actual = a.div(b);
+      expect(actual.mul(b)).toEqual(a);
+    })
+
+    it("Should succeed when mod inverse is +ve", () => {
+      const a = new Fr(10);
+      const b = new Fr(5);
+      const expected = new Fr(2);
+
+      const actual = a.div(b);
+      expect(actual.mul(b)).toEqual(a);
+      expect(actual).toEqual(expected);
+    })
+
+    it("Should not allow a division by 0", () => {
+      const a = new Fr(10);
+      const b = Fr.ZERO;
+
+      expect(() => a.div(b)).toThrowError();
+    })
+  })
+})

From f2f01176d70fd0b5e6c8d886b0867b4e79c607bd Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 17:36:12 +0000
Subject: [PATCH 11/12] fmt

---
 .../foundation/src/fields/fields.test.ts      | 61 +++++++++----------
 1 file changed, 30 insertions(+), 31 deletions(-)

diff --git a/yarn-project/foundation/src/fields/fields.test.ts b/yarn-project/foundation/src/fields/fields.test.ts
index f8ad991a245..c2673ff86e9 100644
--- a/yarn-project/foundation/src/fields/fields.test.ts
+++ b/yarn-project/foundation/src/fields/fields.test.ts
@@ -1,4 +1,4 @@
-import { GrumpkinScalar, Fr } from './fields.js';
+import { Fr, GrumpkinScalar } from './fields.js';
 
 describe('GrumpkinScalar Serialization', () => {
   // Test case for GrumpkinScalar.fromHighLow
@@ -54,9 +54,9 @@ describe('GrumpkinScalar Serialization', () => {
   });
 });
 
-describe("Bn254 arithmetic", () => {
-  describe("Addition", () => {
-    it("Low Boundary", () => {
+describe('Bn254 arithmetic', () => {
+  describe('Addition', () => {
+    it('Low Boundary', () => {
       // 0 + -1 = -1
       const a = Fr.ZERO;
       const b = new Fr(Fr.MODULUS - 1n);
@@ -64,9 +64,9 @@ describe("Bn254 arithmetic", () => {
 
       const actual = a.add(b);
       expect(actual).toEqual(expected);
-    })
+    });
 
-    it("High Boundary", () => {
+    it('High Boundary', () => {
       // -1 + 1 = 0
       const a = new Fr(Fr.MODULUS - 1n);
       const b = new Fr(1);
@@ -76,18 +76,18 @@ describe("Bn254 arithmetic", () => {
       expect(actual).toEqual(expected);
     });
 
-    it("Performs addition correctly", () => {
+    it('Performs addition correctly', () => {
       const a = new Fr(2);
       const b = new Fr(3);
       const expected = new Fr(5);
 
       const actual = a.add(b);
       expect(actual).toEqual(expected);
-    })
-  })
+    });
+  });
 
-  describe("Subtraction", () => {
-    it("Low Boundary", () => {
+  describe('Subtraction', () => {
+    it('Low Boundary', () => {
       // 0 - 1 = -1
       const a = new Fr(0);
       const b = new Fr(1);
@@ -95,18 +95,18 @@ describe("Bn254 arithmetic", () => {
 
       const actual = a.sub(b);
       expect(actual).toEqual(expected);
-    })
+    });
 
-    it("High Bonudary", () => {
+    it('High Bonudary', () => {
       // -1 - (-1) = 0
       const a = new Fr(Fr.MODULUS - 1n);
       const b = new Fr(Fr.MODULUS - 1n);
 
       const actual = a.sub(b);
       expect(actual).toEqual(Fr.ZERO);
-    })
+    });
 
-    it("Performs subtraction correctly", () => {
+    it('Performs subtraction correctly', () => {
       const a = new Fr(10);
       const b = new Fr(5);
       const expected = new Fr(5);
@@ -114,10 +114,10 @@ describe("Bn254 arithmetic", () => {
       const actual = a.sub(b);
       expect(actual).toEqual(expected);
     });
-  })
+  });
 
-  describe("Multiplication", () => {
-    it("Identity", () => {
+  describe('Multiplication', () => {
+    it('Identity', () => {
       const a = new Fr(Fr.MODULUS - 1n);
       const b = new Fr(1);
       const expected = new Fr(Fr.MODULUS - 1n);
@@ -126,7 +126,7 @@ describe("Bn254 arithmetic", () => {
       expect(actual).toEqual(expected);
     });
 
-    it("Performs multiplication correctly", () => {
+    it('Performs multiplication correctly', () => {
       const a = new Fr(2);
       const b = new Fr(3);
       const expected = new Fr(6);
@@ -135,7 +135,7 @@ describe("Bn254 arithmetic", () => {
       expect(actual).toEqual(expected);
     });
 
-    it("High Boundary", () => {
+    it('High Boundary', () => {
       const a = new Fr(Fr.MODULUS - 1n);
       const b = new Fr(Fr.MODULUS / 2n);
       const expected = new Fr(10944121435919637611123202872628637544274182200208017171849102093287904247809n);
@@ -143,19 +143,18 @@ describe("Bn254 arithmetic", () => {
       const actual = a.mul(b);
       expect(actual).toEqual(expected);
     });
-  })
-
+  });
 
-  describe("Division", () => {
-    it("Should succeed when mod inverse is -ve", () => {
+  describe('Division', () => {
+    it('Should succeed when mod inverse is -ve', () => {
       const a = new Fr(2);
       const b = new Fr(3);
 
       const actual = a.div(b);
       expect(actual.mul(b)).toEqual(a);
-    })
+    });
 
-    it("Should succeed when mod inverse is +ve", () => {
+    it('Should succeed when mod inverse is +ve', () => {
       const a = new Fr(10);
       const b = new Fr(5);
       const expected = new Fr(2);
@@ -163,13 +162,13 @@ describe("Bn254 arithmetic", () => {
       const actual = a.div(b);
       expect(actual.mul(b)).toEqual(a);
       expect(actual).toEqual(expected);
-    })
+    });
 
-    it("Should not allow a division by 0", () => {
+    it('Should not allow a division by 0', () => {
       const a = new Fr(10);
       const b = Fr.ZERO;
 
       expect(() => a.div(b)).toThrowError();
-    })
-  })
-})
+    });
+  });
+});

From 059432bbbafa3df2ed047a103180b21f9eb0c4ef Mon Sep 17 00:00:00 2001
From: Maddiaa0 <47148561+Maddiaa0@users.noreply.github.com>
Date: Wed, 7 Feb 2024 18:24:58 +0000
Subject: [PATCH 12/12] fix

---
 yarn-project/simulator/src/avm/opcodes/instruction.ts | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/yarn-project/simulator/src/avm/opcodes/instruction.ts b/yarn-project/simulator/src/avm/opcodes/instruction.ts
index 66396bed7d3..afe7f6e5209 100644
--- a/yarn-project/simulator/src/avm/opcodes/instruction.ts
+++ b/yarn-project/simulator/src/avm/opcodes/instruction.ts
@@ -62,8 +62,3 @@ export abstract class Instruction {
     return new this(...args);
   }
 }
-
-type InstructionConstructor = {
-  new (...args: any[]): Instruction;
-  wireFormat?: OperandType[];
-};