JakobJingleheimer · Mar 20, 2026 · Mar 3, 2026 · Mar 3, 2026 · Mar 3, 2026 · Mar 14, 2026
diff --git a/package-lock.json b/package-lock.json
diff --git a/recipes/mock-module-exports/README.md b/recipes/mock-module-exports/README.md
@@ -0,0 +1,19 @@
+# Mock Module Exports
+
+This migration trasforming use of deprecated `options.defaultExport` and `options.namedExports` on
+`node:test.mock`
+
+## Example
+
+```diff
+mock.module('…', {
+-   defaultExport: …,
+-   namedExports: {
+-   	foo: …
+-   },
++   exports: {
++   	default: …,
++   	foo: …,
++   },
+});
+```
diff --git a/recipes/mock-module-exports/codemod.yaml b/recipes/mock-module-exports/codemod.yaml
@@ -0,0 +1,21 @@
+schema_version: "1.0"
+name: "@nodejs/mock-module-exports"
+version: 1.0.0
+description: "Handle mock.module exports deprecation"
+author: Bruno Rodrigues
+license: MIT
+workflow: workflow.yaml
+category: migration
+
+targets:
+  languages:
+    - javascript
+    - typescript
+
+keywords:
+  - transformation
+  - migration
+
+registry:
+  access: public
+  visibility: public
diff --git a/recipes/mock-module-exports/package.json b/recipes/mock-module-exports/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "@nodejs/mock-module-exports",
+  "version": "1.0.0",
+  "description": "Handle mock.module exports deprecation",
+  "type": "module",
+  "scripts": {
+    "test": "npx codemod jssg test -l typescript ./src/workflow.ts ./tests/"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/nodejs/userland-migrations.git",
+    "directory": "recipes/mock-module-exports",
+    "bugs": "https://github.com/nodejs/userland-migrations/issues"
+  },
+  "author": "Bruno Rodrigues",
+  "license": "MIT",
+  "homepage": "https://github.com/nodejs/userland-migrations/blob/main/recipes/mock-module-exports/README.md",
+  "devDependencies": {
+    "@codemod.com/jssg-types": "^1.3.1"
+  },
+  "dependencies": {
+    "@nodejs/codemod-utils": "*"
+  }
+}
diff --git a/recipes/mock-module-exports/src/workflow.ts b/recipes/mock-module-exports/src/workflow.ts
@@ -0,0 +1,281 @@
+import type { SgRoot, Edit, SgNode, Kinds } from '@codemod.com/jssg-types/main';
+import type JS from '@codemod.com/jssg-types/langs/javascript';
+import { getModuleDependencies } from '@nodejs/codemod-utils/ast-grep/module-dependencies';
+import { resolveBindingPath } from '@nodejs/codemod-utils/ast-grep/resolve-binding-path';
+import {
+	detectIndentUnit,
+	getLineIndent,
+} from '@nodejs/codemod-utils/ast-grep/indent';
+import { EOL } from 'node:os';
+
+type QueueEvent = {
+	event: keyof typeof parsers;
+	handler: () => void;
+};
+
+const queue: QueueEvent[] = [];
+
+type Pair = {
+	before: SgNode<JS, 'pair'> | SgNode<JS, 'spread_element'>;
+	after: string;
+};
+
+type ExportedValue = {
+	node: SgNode<JS, Kinds<JS>>;
+	default: Pair;
+	named: Pair[] | undefined;
+};
+const exportedValues: Map<number, ExportedValue> = new Map();
+
+const parsers = {
+	parseOptions: (optionsNode: SgNode<JS, Kinds<JS>>) => {
+		switch (optionsNode.kind()) {
+			case 'object':
+				queue.push(
+					{
+						event: 'defaultExport',
+						handler: () => parsers.defaultExport(optionsNode),
+					},
+					{
+						event: 'namedExports',
+						handler: () => parsers.namedExports(optionsNode),
+					},
+					{
+						event: 'spreadElements',
+						handler: () => parsers.spreadElements(optionsNode),
+					},
+				);
+				break;
+			case 'identifier':
+				queue.push({
+					event: 'resolveVariables',
+					handler: () => parsers.resolveVariables(optionsNode),
+				});
+				break;
+			case 'call_expression':
+				queue.push({
+					event: 'resolveVariables',
+					handler: () =>
+						parsers.resolveVariables(optionsNode.field('function')),
+				});
+				break;
+		}
+	},
+	resolveVariables: (node: SgNode<JS, Kinds<JS>>) => {
+		const definition = node.definition();
+		if (!definition) return;
+
+		switch (definition.node.parent().kind()) {
+			case 'variable_declarator': {
+				const parent = definition.node.parent<'variable_declarator'>();
+				queue.push({
+					event: 'parseOptions',
+					handler: () => parsers.parseOptions(parent.field('value')),
+				});
+				break;
+			}
+			case 'function_declaration': {
+				const fnDeclaration = definition.node.parent<'variable_declarator'>();
+
+				const returns = fnDeclaration
+					.findAll<'return_statement'>({
+						rule: {
+							kind: 'return_statement',
+						},
+					})
+					.map((n) => n.child(1));
+
+				for (const ret of returns) {
+					if (ret) {
+						queue.push({
+							event: 'parseOptions',
+							handler: () => parsers.parseOptions(ret),
+						});
+					}
+				}
+
+				break;
+			}
+			default:
+				throw new Error('unhandled scenario');
+		}
+	},
+	defaultExport: (node: SgNode<JS, Kinds<JS>>): Edit[] => {
+		const edits: Edit[] = [];
+		const defaultExport = node.find<'pair'>({
+			rule: {
+				kind: 'pair',
+				has: {
+					field: 'key',
+					kind: 'property_identifier',
+					regex: 'defaultExport',
+				},
+			},
+		});
+		if (defaultExport) {
+			const change = {
+				before: defaultExport,
+				after: `default: ${defaultExport?.field('value').text()}`,
+			};
+
+			if (!exportedValues.has(node.id())) {
+				exportedValues.set(node.id(), {
+					node,
+					default: change,
+					named: [],
+				});
+				return;
+			}
+
+			const n = exportedValues.get(node.id());
+			n.default = change;
+		}
+		return edits;
+	},
+	namedExports: (node: SgNode<JS, Kinds<JS>>) => {
+		const namedExport = node.find<'pair'>({
+			rule: {
+				kind: 'pair',
+				has: {
+					field: 'key',
+					kind: 'property_identifier',
+					regex: 'namedExport',
+				},
+			},
+		});
+
+		if (namedExport) {
+			if (!exportedValues.has(node.id())) {
+				exportedValues.set(node.id(), {
+					node,
+					default: undefined,
+					named: [],
+				});
+			}
+
+			const pairs = exportedValues.get(node.id()).named;
+
+			const fieldValueNode = namedExport.field('value');
+
+			if (fieldValueNode.is('identifier')) {
+				pairs.push({
+					before: namedExport,
+					after: `...(${fieldValueNode.text()} || {})`,
+				});
+			}
+			for (const namedPair of fieldValueNode.children()) {
+				if (namedPair.is('pair')) {
+					pairs.push({
+						before: namedPair,
+						after: namedPair.text(),
+					});
+				}
+			}
+		}
+	},
+	spreadElements: (node: SgNode<JS, Kinds<JS>>): undefined => {
+		const spreadElements = node.findAll<'spread_element'>({
+			rule: {
+				kind: 'spread_element',
+			},
+		});
+
+		if (spreadElements) {
+			if (!exportedValues.has(node.id())) {
+				exportedValues.set(node.id(), {
+					node,
+					default: undefined,
+					named: [],
+				});
+			}
+
+			const pairs = exportedValues.get(node.id()).named;
+
+			for (const spread of spreadElements) {
+				pairs.push({
+					before: spread,
+					after: spread.text(),
+				});
+			}
+		}
+	},
+} as const satisfies Record<string, (node: SgNode<JS, Kinds<JS>>) => void>;
+
+export default function transform(root: SgRoot<JS>): string | null {
+	const rootNode = root.root();
+	const edits: Edit[] = [];
+
+	const deps = getModuleDependencies(root, 'test');
+	let moduleFnCalls: SgNode<JS, 'call_expression'>[] = [];
+
+	if (!deps.length) return null;
+
+	for (const dep of deps) {
+		const moduleFn = resolveBindingPath(dep, '$.mock.module');
+
+		const fnCallNodes = rootNode.findAll<'call_expression'>({
+			rule: {
+				kind: 'call_expression',
+				has: {
+					any: [
+						{
+							kind: 'member_expression',
+							pattern: moduleFn,
+						},
+					],
+				},
+			},
+		});
+
+		moduleFnCalls = moduleFnCalls.concat(fnCallNodes);
+	}
+
+	for (const moduleFnCall of moduleFnCalls) {
+		const argumentsNode = moduleFnCall.field<'arguments'>('arguments');
+		const args = argumentsNode.children().filter((node) => node.isNamed());
+
+		if (args.length < 2) continue;
+		const optionsArg = args[1];
+		queue.push({
+			event: 'parseOptions',
+			handler: () => parsers.parseOptions(optionsArg),
+		});
+	}
+
+	const indentUnit = detectIndentUnit(rootNode.text());
+
+	let i = 0;
+	while (queue.length > i) {
+		const event = queue.at(i);
+		event.handler();
+		i++;
+	}
+
+	for (const [_nodeId, change] of Array.from(exportedValues)) {
+		const indentLevel = getLineIndent(
+			rootNode.text(),
+			change.node.range().start.index,
+		);
+
+		const exportsLevel = `${indentLevel}${indentUnit}`;
+		const innerExports = `${exportsLevel}${indentUnit}`;
+
+		let newValue = `{${EOL}` + `${exportsLevel}exports: {${EOL}`;
+
+		if (change.default?.after) {
+			newValue += `${innerExports}${change.default.after},${EOL}`;
+		}
+
+		if (change.named?.length) {
+			newValue += `${innerExports}${change.named.map((t) => t.after).join(`,${EOL}${innerExports}`)},${EOL}`;
+		}
+
+		newValue += `${exportsLevel}},${EOL}` + `${indentLevel}}`;
+
+		edits.push(change.node.replace(newValue));
+	}
+
+	if (!edits.length) return null;
+
+	return rootNode.commitEdits(edits);
+}