diff --git a/packages/editor-ui/src/composables/useWorkflowHelpers.ts b/packages/editor-ui/src/composables/useWorkflowHelpers.ts
index 1c74fad47a0a3..ee75c6d8ca51f 100644
--- a/packages/editor-ui/src/composables/useWorkflowHelpers.ts
+++ b/packages/editor-ui/src/composables/useWorkflowHelpers.ts
@@ -69,7 +69,7 @@ import type { useRouter } from 'vue-router';
 import { useTelemetry } from '@/composables/useTelemetry';
 import { useProjectsStore } from '@/features/projects/projects.store';
 
-export function resolveParameter(
+export function resolveParameter<T = IDataObject>(
 	parameter: NodeParameterValue | INodeParameters | NodeParameterValue[] | INodeParameters[],
 	opts: {
 		targetItem?: TargetItem;
@@ -79,7 +79,7 @@ export function resolveParameter(
 		additionalKeys?: IWorkflowDataProxyAdditionalKeys;
 		isForCredential?: boolean;
 	} = {},
-): IDataObject | null {
+): T | null {
 	let itemIndex = opts?.targetItem?.itemIndex || 0;
 
 	const workflow = getCurrentWorkflow();
@@ -115,7 +115,7 @@ export function resolveParameter(
 			false,
 			undefined,
 			'',
-		) as IDataObject;
+		) as T;
 	}
 
 	const inputName = NodeConnectionType.Main;
@@ -235,7 +235,7 @@ export function resolveParameter(
 		false,
 		{},
 		contextNode!.name,
-	) as IDataObject;
+	) as T;
 }
 
 export function resolveRequiredParameters(
diff --git a/packages/editor-ui/src/plugins/codemirror/completions/__tests__/completions.test.ts b/packages/editor-ui/src/plugins/codemirror/completions/__tests__/completions.test.ts
index d1d1ca6d6008c..0f8f41c899286 100644
--- a/packages/editor-ui/src/plugins/codemirror/completions/__tests__/completions.test.ts
+++ b/packages/editor-ui/src/plugins/codemirror/completions/__tests__/completions.test.ts
@@ -119,14 +119,12 @@ describe('Top-level completions', () => {
 
 describe('Luxon method completions', () => {
 	test('should return class completions for: {{ DateTime.| }}', () => {
-		// @ts-expect-error Spied function is mistyped
 		vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(DateTime);
 
 		expect(completions('{{ DateTime.| }}')).toHaveLength(luxonStaticOptions().length);
 	});
 
 	test('should return instance completions for: {{ $now.| }}', () => {
-		// @ts-expect-error Spied function is mistyped
 		vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(DateTime.now());
 
 		expect(completions('{{ $now.| }}')).toHaveLength(
@@ -138,7 +136,6 @@ describe('Luxon method completions', () => {
 	});
 
 	test('should return instance completions for: {{ $today.| }}', () => {
-		// @ts-expect-error Spied function is mistyped
 		vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(DateTime.now());
 
 		expect(completions('{{ $today.| }}')).toHaveLength(
@@ -153,7 +150,6 @@ describe('Luxon method completions', () => {
 describe('Resolution-based completions', () => {
 	describe('literals', () => {
 		test('should return completions for string literal: {{ "abc".| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('abc');
 
 			expect(completions('{{ "abc".| }}')).toHaveLength(
@@ -164,7 +160,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for boolean literal: {{ true.| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(true);
 
 			expect(completions('{{ true.| }}')).toHaveLength(
@@ -173,7 +168,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should properly handle string that contain dollar signs', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce("You 'owe' me 200$ ");
 
 			const result = completions('{{ "You \'owe\' me 200$".| }}');
@@ -184,7 +178,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for number literal: {{ (123).| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(123);
 
 			expect(completions('{{ (123).| }}')).toHaveLength(
@@ -195,7 +188,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for array literal: {{ [1, 2, 3].| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce([1, 2, 3]);
 
 			expect(completions('{{ [1, 2, 3].| }}')).toHaveLength(
@@ -204,7 +196,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for Object methods: {{ Object.values({ abc: 123 }).| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce([123]);
 
 			const found = completions('{{ Object.values({ abc: 123 }).| }}');
@@ -229,7 +220,6 @@ describe('Resolution-based completions', () => {
 
 	describe('indexed access completions', () => {
 		test('should return string completions for indexed access that resolves to string literal: {{ "abc"[0].| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('a');
 
 			expect(completions('{{ "abc"[0].| }}')).toHaveLength(
@@ -244,7 +234,7 @@ describe('Resolution-based completions', () => {
 		const { $input } = mockProxy;
 
 		test('should return completions when $input is used as a function parameter', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.num);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.num);
 			const found = completions('{{ Math.abs($input.item.json.num1).| }}');
 			if (!found) throw new Error('Expected to find completions');
 			expect(found).toHaveLength(
@@ -273,7 +263,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for complex expression: {{ $execution.resumeUrl.includes($json.) }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce($input.item.json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce($input.item?.json);
 			const { $json } = mockProxy;
 			const found = completions('{{ $execution.resumeUrl.includes($json.|) }}');
 
@@ -284,7 +274,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for operation expression: {{ $now.day + $json. }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce($input.item.json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce($input.item?.json);
 			const { $json } = mockProxy;
 			const found = completions('{{ $now.day + $json.| }}');
 
@@ -296,7 +286,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for operation expression: {{ Math.abs($now.day) >= 10 ? $now : Math.abs($json.). }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json);
 			const { $json } = mockProxy;
 			const found = completions('{{ Math.abs($now.day) >= 10 ? $now : Math.abs($json.|) }}');
 
@@ -312,7 +302,7 @@ describe('Resolution-based completions', () => {
 		const { $input } = mockProxy;
 
 		test('should return bracket-aware completions for: {{ $input.item.json.str.|() }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.str);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.str);
 
 			const found = completions('{{ $input.item.json.str.|() }}');
 
@@ -327,7 +317,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return bracket-aware completions for: {{ $input.item.json.num.|() }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.num);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.num);
 
 			const found = completions('{{ $input.item.json.num.|() }}');
 
@@ -342,7 +332,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return bracket-aware completions for: {{ $input.item.json.arr.| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.arr);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.arr);
 
 			const found = completions('{{ $input.item.json.arr.|() }}');
 
@@ -477,7 +467,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for: {{ $input.all().| }}', () => {
-			// @ts-expect-error
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue([$input.item]);
 
 			expect(completions('{{ $input.all().| }}')).toHaveLength(
@@ -488,26 +477,26 @@ describe('Resolution-based completions', () => {
 		});
 
 		test("should return completions for: '{{ $input.item.| }}'", () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json);
 
 			expect(completions('{{ $input.item.| }}')).toHaveLength(
-				Object.keys($input.item.json).length + extensions({ typeName: 'object' }).length,
+				Object.keys($input.item?.json ?? {}).length + extensions({ typeName: 'object' }).length,
 			);
 		});
 
 		test("should return completions for: '{{ $input.first().| }}'", () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.first().json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.first()?.json);
 
 			expect(completions('{{ $input.first().| }}')).toHaveLength(
-				Object.keys($input.first().json).length + extensions({ typeName: 'object' }).length,
+				Object.keys($input.first()?.json ?? {}).length + extensions({ typeName: 'object' }).length,
 			);
 		});
 
 		test("should return completions for: '{{ $input.last().| }}'", () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.last().json);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.last()?.json);
 
 			expect(completions('{{ $input.last().| }}')).toHaveLength(
-				Object.keys($input.last().json).length + extensions({ typeName: 'object' }).length,
+				Object.keys($input.last()?.json ?? {}).length + extensions({ typeName: 'object' }).length,
 			);
 		});
 
@@ -520,7 +509,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for: {{ $input.item.json.str.| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.str);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.str);
 
 			expect(completions('{{ $input.item.json.str.| }}')).toHaveLength(
 				extensions({ typeName: 'string' }).length +
@@ -530,7 +519,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for: {{ $input.item.json.num.| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.num);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.num);
 
 			expect(completions('{{ $input.item.json.num.| }}')).toHaveLength(
 				extensions({ typeName: 'number' }).length +
@@ -540,7 +529,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for: {{ $input.item.json.arr.| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.arr);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.arr);
 
 			expect(completions('{{ $input.item.json.arr.| }}')).toHaveLength(
 				extensions({ typeName: 'array' }).length + natives({ typeName: 'array' }).length,
@@ -548,10 +537,10 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should return completions for: {{ $input.item.json.obj.| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.obj);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.obj);
 
 			expect(completions('{{ $input.item.json.obj.| }}')).toHaveLength(
-				Object.keys($input.item.json.obj).length + extensions({ typeName: 'object' }).length,
+				Object.keys($input.item?.json.obj ?? {}).length + extensions({ typeName: 'object' }).length,
 			);
 		});
 	});
@@ -561,26 +550,26 @@ describe('Resolution-based completions', () => {
 
 		['{{ $input.item.json[| }}', '{{ $json[| }}'].forEach((expression) => {
 			test(`should return completions for: ${expression}`, () => {
-				vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json);
+				vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json);
 
 				const found = completions(expression);
 
 				if (!found) throw new Error('Expected to find completions');
 
-				expect(found).toHaveLength(Object.keys($input.item.json).length);
+				expect(found).toHaveLength(Object.keys($input.item?.json ?? {}).length);
 				expect(found.map((c) => c.label).every((l) => l.endsWith(']')));
 			});
 		});
 
 		["{{ $input.item.json['obj'][| }}", "{{ $json['obj'][| }}"].forEach((expression) => {
 			test(`should return completions for: ${expression}`, () => {
-				vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item.json.obj);
+				vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValue($input.item?.json.obj);
 
 				const found = completions(expression);
 
 				if (!found) throw new Error('Expected to find completions');
 
-				expect(found).toHaveLength(Object.keys($input.item.json.obj).length);
+				expect(found).toHaveLength(Object.keys($input.item?.json.obj ?? {}).length);
 				expect(found.map((c) => c.label).every((l) => l.endsWith(']')));
 			});
 		});
@@ -625,7 +614,6 @@ describe('Resolution-based completions', () => {
 
 	describe('recommended completions', () => {
 		test('should recommend toDateTime() for {{ "1-Feb-2024".| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('1-Feb-2024');
 
 			expect(completions('{{ "1-Feb-2024".| }}')?.[0]).toEqual(
@@ -634,7 +622,6 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend toNumber() for: {{ "5.3".| }}', () => {
-			// @ts-expect-error Spied function is mistyped
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('5.3');
 			const options = completions('{{ "5.3".| }}');
 			expect(options?.[0]).toEqual(
@@ -644,7 +631,6 @@ describe('Resolution-based completions', () => {
 
 		test('should recommend extractEmail() for: {{ "string with test@n8n.io in it".| }}', () => {
 			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
 				'string with test@n8n.io in it',
 			);
 			const options = completions('{{ "string with test@n8n.io in it".| }}');
@@ -654,10 +640,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend extractDomain(), isEmail() for: {{ "test@n8n.io".| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				'test@n8n.io',
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('test@n8n.io');
 			const options = completions('{{ "test@n8n.io".| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: 'extractDomain()', section: RECOMMENDED_SECTION }),
@@ -668,10 +651,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend extractDomain(), extractUrlPath() for: {{ "https://n8n.io/pricing".| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				'https://n8n.io/pricing',
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('https://n8n.io/pricing');
 			const options = completions('{{ "https://n8n.io/pricing".| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: 'extractDomain()', section: RECOMMENDED_SECTION }),
@@ -682,10 +662,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend round(),floor(),ceil() for: {{ (5.46).| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				5.46,
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(5.46);
 			const options = completions('{{ (5.46).| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: 'round()', section: RECOMMENDED_SECTION }),
@@ -699,10 +676,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test("should recommend toDateTime('s') for: {{ (1900062210).| }}", () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				1900062210,
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(1900062210);
 			const options = completions('{{ (1900062210).| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: "toDateTime('s')", section: RECOMMENDED_SECTION }),
@@ -710,10 +684,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test("should recommend toDateTime('ms') for: {{ (1900062210000).| }}", () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				1900062210000,
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(1900062210000);
 			const options = completions('{{ (1900062210000).| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: "toDateTime('ms')", section: RECOMMENDED_SECTION }),
@@ -721,10 +692,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend toBoolean() for: {{ (0).| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				0,
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(0);
 			const options = completions('{{ (0).| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: 'toBoolean()', section: RECOMMENDED_SECTION }),
@@ -732,10 +700,7 @@ describe('Resolution-based completions', () => {
 		});
 
 		test('should recommend toBoolean() for: {{ "true".| }}', () => {
-			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce(
-				// @ts-expect-error Spied function is mistyped
-				'true',
-			);
+			vi.spyOn(workflowHelpers, 'resolveParameter').mockReturnValueOnce('true');
 			const options = completions('{{ "true".| }}');
 			expect(options?.[0]).toEqual(
 				expect.objectContaining({ label: 'toBoolean()', section: RECOMMENDED_SECTION }),
@@ -746,9 +711,7 @@ describe('Resolution-based completions', () => {
 	describe('explicit completions (opened by Ctrl+Space or programatically)', () => {
 		test('should return completions for: {{ $json.foo| }}', () => {
 			vi.spyOn(workflowHelpers, 'resolveParameter')
-				// @ts-expect-error Spied function is mistyped
 				.mockReturnValueOnce(undefined)
-				// @ts-expect-error Spied function is mistyped
 				.mockReturnValueOnce('foo');
 
 			const result = completions('{{ $json.foo| }}', true);
diff --git a/packages/editor-ui/src/plugins/codemirror/completions/bracketAccess.completions.ts b/packages/editor-ui/src/plugins/codemirror/completions/bracketAccess.completions.ts
index a922b1354cdf5..6c018ef8e80a6 100644
--- a/packages/editor-ui/src/plugins/codemirror/completions/bracketAccess.completions.ts
+++ b/packages/editor-ui/src/plugins/codemirror/completions/bracketAccess.completions.ts
@@ -1,6 +1,5 @@
 import { resolveParameter } from '@/composables/useWorkflowHelpers';
 import { prefixMatch, longestCommonPrefix } from './utils';
-import type { IDataObject } from 'n8n-workflow';
 import type { Completion, CompletionContext, CompletionResult } from '@codemirror/autocomplete';
 import type { Resolved } from './types';
 import { escapeMappingString } from '@/utils/mappingUtils';
@@ -37,7 +36,7 @@ export function bracketAccessCompletions(context: CompletionContext): Completion
 		return null;
 	}
 
-	if (resolved === null || resolved === undefined) return null;
+	if (resolved === null || resolved === undefined || typeof resolved !== 'object') return null;
 
 	let options = bracketAccessOptions(resolved);
 
@@ -59,7 +58,7 @@ export function bracketAccessCompletions(context: CompletionContext): Completion
 	};
 }
 
-function bracketAccessOptions(resolved: IDataObject) {
+function bracketAccessOptions(resolved: object) {
 	const SKIP = new Set(['__ob__', 'pairedItem']);
 
 	return Object.keys(resolved)