Add example smart contracts with comprehensive README.

contracts/.gitignore

@@ -0,0 +1,2 @@
+bulletin_board/target
+highlighted_posts/target

contracts/README.md

@@ -12,7 +12,6 @@
 * [When to use `panic!`/`assert!` and when return a `Result`.](#panic-and-when-to-return-a-result)
 * [What are selectors and how to use them.](#call-another-contract-and-handle-the-response)
 * [How to call another contract and handle the response.](#call-another-contract-and-handle-the-response)
-* [How to test cross-contract calls.](#test-a-cross-contract-call)
 * [How to build a contract and optimize it.](#build-your-local-contract-with-optimizations)
 * [How to deploy a contract using Contracts UI. And interact with it.](#deploy-a-contract-using-contracts-ui)
 * [How to deploy a contract to custom environment.](#deploying-example-contracts-using-scripts)
@@ -23,13 +22,7 @@ Let's start..
 
 ## Setting up the environment
 
-### Install Rust & Cargo
-
-A prerequisite is to have Rust and Cargo installed. Please follow [the official guide](https://doc.rust-lang.org/cargo/getting-started/installation.html).
-
-### ink!
-
-We will need to install ink! dependencies: binaryen, and ink! contract linters. Finally a `cargo contract`. All these steps are described in the [ink! documentation](https://doc.rust-lang.org/cargo/getting-started/installation.html).
+To set up the environment before, please follow the guide from [our documentation](https://docs.alephzero.org/smart-contracts-tutorial/installing-required-tools).
 
 ## Example contracts
 
@@ -48,8 +41,12 @@ in respective root folders (`/bulletin_board` and `highlighted_posts`). Verify t
 * `*.wasm` -- the actual logic of the contract compiled into WASM code.
 * `*.contract` -- the two above bundled up.
 
+Note the lack of `+nightly`, in the above command, which is suggested in most guides - that's b/c we've specified the version of toolchain being used in the `rust-toolchain` files.
+
 ### Deploying
 
+Tutorial below will explain how to develop and test smart contracts using either the local Aleph Zero network or already-existing one, here we will be using our [Testnet](https://test.azero.dev/).
+
 #### Prerequisities for interacting with Aleph Zero Testnet
 
 1. Install PolkadotJS browser extension.
@@ -108,17 +105,17 @@ For Testnet (or any other network for that matter), you will have to fill in the
 ### Emit events and verify in tests you did
 
 #### Creating and emitting events
-See `lib.rs` for `#[ink(event)]` on how to define it and [`fn emit_event`](./bulletin_board/lib.rs#L462) to see how to emit it.
+See `lib.rs` for `#[ink(event)]` on how to define it and [`fn emit_event`](./bulletin_board/lib.rs#L465) to see how to emit it.
 
-> Thing to note here is the custom `emit_event` function - you may have seen in official ink! documentation that events are emitted via `self::env().emit_event(my_event)` calls. The "official" version works when there is only one contract emitting events on our _execution path_. If our contract emits events and, during execution, calls another contract that emits events AND we have that contract as a dependency, we will have two unreleated event families (from two different contracts) and the compiler will fail to resolve type boundaries correctly. For more details, see comments on [`fn emit_event`](./bulletin_board/lib.rs#L462).
+> Thing to note here is the custom `emit_event` function - you may have seen in official ink! documentation that events are emitted via `self::env().emit_event(my_event)` calls. The "official" version works when there is only one contract emitting events on our _execution path_. If our contract emits events and, during execution, calls another contract that emits events AND we have that contract as a dependency, we will have two unreleated event families (from two different contracts) and the compiler will fail to resolve type boundaries correctly. For more details, see comments on [`fn emit_event`](./bulletin_board/lib.rs#L465).
 
 #### Testing the events were emitted
 
-In `lib.rs` look for calls to [`recorded_events()`](./bulletin_board/lib.rs#L579), to collect the emitted events, and [`assert_expected_*_event`](./bulletin_board/lib.rs#L580) to test whether we got the expected ones.
+In `lib.rs` look for calls to [`recorded_events()`](./bulletin_board/lib.rs#L582), to collect the emitted events, and [`assert_expected_*_event`](./bulletin_board/lib.rs#L583) to test whether we got the expected ones.
 
 ### Do logging in your contract
 
-In `lib.rs` see [invocation](./bulletin_board/lib.rs#L233) of `ink_env::debug_println!` - this will produce a log message when ran in test. To verify, run [`event_on_post`](./bulletin_board/lib.rs#L574) test and observe the following log:
+In `lib.rs` see [invocation](./bulletin_board/lib.rs#L236) of `ink_env::debug_println!` - this will produce a log message when ran in test. To verify, run [`event_on_post`](./bulletin_board/lib.rs#L577) test and observe the following log:
 ```shell
 running 1 test
 `AccountId([1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1])` wants to create a post that expires after `100` blocks with the text `"Text"`
@@ -137,19 +134,19 @@ All you need is a code hash of the other contract you want to instantiate. See a
 
 ### Transfer tokens as part of a contract call
 
-If you want your method to accept token transfer, you need to tag it with `payable` keyword: `#[ink(payable)]`. See [`BulletinBoard::post`](./bulletin_board/lib.rs#L222) for an example.
+If you want your method to accept token transfer, you need to tag it with `payable` keyword: `#[ink(payable)]`. See [`BulletinBoard::post`](./bulletin_board/lib.rs#L225) for an example.
 
-For an example on how to do a cross-contract call _and_ transfer tokens, see [`highlight_post`](./bulletin_board/lib.rs#L406).
+For an example on how to do a cross-contract call _and_ transfer tokens, see [`highlight_post`](./bulletin_board/lib.rs#L409).
 
 ### Unit test a contract
 
-See [`bulletin_board::tests`](./bulletin_board/lib.rs#L493) for various tests, including mocking the blockchain environment - setting caller, token balance, etc.
+See [`bulletin_board::tests`](./bulletin_board/lib.rs#L496) for various tests, including mocking the blockchain environment - setting caller, token balance, etc.
 
 ### Terminate a contract (and why)
 
 If you want to delete an instance of the contract because it's incorrect, no longer needed (and we want to free the storage) or for any other reason we can do it by _terminating_ a contract.
 
-To delete an instance of the contract, call `self.env().terminate_contract(<beneficiary>)`. You can choose the _beneficiary_ that will receive tokens that the contract owns. For the example, see [`terminate_contract`](./bulletin_board/lib.rs#L314).
+To delete an instance of the contract, call `self.env().terminate_contract(<beneficiary>)`. You can choose the _beneficiary_ that will receive tokens that the contract owns. For the example, see [`terminate_contract`](./bulletin_board/lib.rs#L317).
 
 ### `panic!` and when to return a `Result`
 
@@ -167,8 +164,8 @@ Every contract _instance_ is stored under an address of type `AccountId`. To cal
 
 Calling another contract can be currently made in two ways:
 
-1) Building the call manually. An example of that is [`highlight_post`](./bulletin_board/lib.rs#L412). Here, we set every piece of the call by hand and we have no help from the compiler (to tell us whether we use correct arguments or if the return type is valid). This manual approach gives contract author access to ink!-level [errors](https://docs.rs/ink_env/3.4.0/ink_env/enum.Error.html) which gives an option to recover from the low-level failures.
-2) Using the macro-generated `*Ref` pattern. An example of that is [`delete_highlight`](./bulletin_board/lib.rs#L450). This approach is type-safe but doesn't allow for transferring tokens with the call. At least not currently.
+1) Building the call manually. An example of that is [`highlight_post`](./bulletin_board/lib.rs#L409). Here, we set every piece of the call by hand and we have no help from the compiler (to tell us whether we use correct arguments or if the return type is valid). This manual approach gives contract author access to ink!-level [errors](https://docs.rs/ink_env/3.4.0/ink_env/enum.Error.html) which gives an option to recover from the low-level failures.
+2) Using the macro-generated `*Ref` pattern. An example of that is [`delete_highlight`](./bulletin_board/lib.rs#L446). This approach is type-safe but doesn't allow for transferring tokens with the call. At least not currently.
 
 Both approaches, if done correctly, provide a typed access to another contract.
 

contracts/bulletin_board/lib.rs

@@ -15,7 +15,7 @@
 
 // An entrypoint to all ink! smart contracts.
 // When expanded, this macro will:
-// * Add local type aliases to the `mod notice_pillar`, like `Environment`,
+// * Add local type aliases to the `mod bulletin_board`, like `Environment`,
 //   `AccountId`, `Balance`, `Hash`, `Timestamp` and `BlockNumber`. All will
 //   resolve to defaults `ink_env::DefaultEnvironment::<type>`
 // * Adds useful #[doc] macros
@@ -191,7 +191,10 @@ mod bulletin_board {
             })
         }
 
-        // Constructors can delegate to other constructors.
+        // Contracts can have multiple constructors. You can choose which to use
+        // when instantiating a contract.
+        /// Creates an instance of `BulletinBoard` contract where posting is
+        /// "free".
         #[ink(constructor)]
         pub fn free() -> Self {
             initialize_contract(|instance: &mut BulletinBoard| {

scripts/deploy.sh

@@ -22,4 +22,5 @@ BULLETIN_BOARD=$(cargo contract instantiate --url "$NODE_URL" --suri "$AUTHORITY
 # We're initializing `highlighted_posts` contract in the constructor of `bulletin board` so there will be multiple new contract addresses.
 # `cargo contract` prints the first one, rather than the last one, so we have to extract it from the events.
 BULLETIN_BOARD=$(echo "$BULLETIN_BOARD" | grep -A3 "Event Contracts ➜ Instantiated" | grep contract | tail -1 | cut -d ' ' -f11)
-echo "Bulletin board instance address: $BULLETIN_BOARD"
+echo "Bulletin board instance address: $BULLETIN_BOARD"
+

scripts/deploy_local.sh

@@ -4,4 +4,5 @@ set -euo pipefail
 
 source $(pwd)/scripts/env/local
 
-$(pwd)/scripts/deploy.sh
+$(pwd)/scripts/deploy.sh
+

scripts/deploy_testnet.sh

@@ -4,4 +4,5 @@ set -euo pipefail
 
 source $(pwd)/scripts/env/testnet
 
-$(pwd)/scripts/deploy.sh
+$(pwd)/scripts/deploy.sh
+

scripts/env/local

@@ -1,3 +1,4 @@
 export NODE_URL=ws://localhost:9944
 
-export AUTHORITY_SEED=//Alice
+export AUTHORITY_SEED=//Alice
+

scripts/env/testnet

@@ -1,3 +1,4 @@
 export NODE_URL=wss://ws.test.azero.dev
 
-export AUTHORITY_SEED=
+export AUTHORITY_SEED=
+