feat(bytesRead-to-bytesWritten): implement Node.js DEP0108 migration (#224)

Co-authored-by: Copilot <[email protected]>
Co-authored-by: Augustin Mauroy <[email protected]>
Co-authored-by: Jacob Smith <[email protected]>
Co-authored-by: Bruno Rodrigues <[email protected]>

Author: 5 people

package-lock.json

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+# `zlib.bytesRead` → `zlib.bytesWritten` DEP0108
+
+This codemod replaces zlib.bytesRead with zlib.bytesWritten for consistent stream property naming. It's useful to migrate code that uses the deprecated property which has been removed.
+
+It replaces zlib.bytesRead with zlib.bytesWritten in all zlib transform streams and it handles both CommonJS and ESM imports.
+
+See [DEP0108](https://nodejs.org/api/deprecations.html#DEP0108).
+
+---
+
+## Example
+
+**Case 1**
+
+Before:
+
+```js
+const zlib = require("node:zlib");
+const gzip = zlib.createGzip();
+gzip.on("end", () => {
+  console.log("Bytes processed:", gzip.bytesRead);
+});
+```
+
+After:
+
+```js
+const zlib = require("node:zlib");
+const gzip = zlib.createGzip();
+gzip.on("end", () => {
+  console.log("Bytes processed:", gzip.bytesWritten);
+});
+```
+
+**Case 2**
+
+Before:
+
+```js
+const zlib = require("node:zlib");
+const deflate = zlib.createDeflate();
+deflate.on("finish", () => {
+  const stats = {
+    input: deflate.bytesRead,
+    output: deflate.bytesWritten
+  };
+});
+```
+
+After:
+
+```js
+const zlib = require("node:zlib");
+const deflate = zlib.createDeflate();
+deflate.on("finish", () => {
+  const stats = {
+    input: deflate.bytesWritten,
+    output: deflate.bytesWritten
+  };
+});
+```
+
+**Case 3**
+
+Before:
+
+```js
+const zlib = require("node:zlib");
+function trackProgress(stream) {
+  setInterval(() => {
+    console.log(`Progress: ${stream.bytesRead} bytes`);
+  }, 1000);
+}
+```
+
+After:
+
+```js
+const zlib = require("node:zlib");
+function trackProgress(stream) {
+  setInterval(() => {
+    console.log(`Progress: ${stream.bytesWritten} bytes`);
+  }, 1000);
+}
+```
+
+**Case 4**
+
+Before:
+
+```js
+import { createGzip } from "node:zlib";
+const gzip = createGzip();
+const bytesProcessed = gzip.bytesRead;
+```
+
+After:
+
+```js
+import { createGzip } from "node:zlib";
+const gzip = createGzip();
+const bytesProcessed = gzip.bytesWritten;
+```
+
+**Case 5**
+
+Before:
+
+```js
+const zlib = require("node:zlib");
+const gzip = zlib.createGzip();
+const processed = gzip.bytesRead;
+```
+
+After:
+
+```js
+const zlib = require("node:zlib");
+const gzip = zlib.createGzip();
+const processed = gzip.bytesWritten;
+```
+
+**Case 6**
+
+Before:
+
+```js
+const { createGzip } = require("node:zlib");
+const gzip = createGzip();
+const bytes = gzip.bytesRead;
+```
+
+After:
+
+```js
+const { createGzip } = require("node:zlib");
+const gzip = createGzip();
+const bytes = gzip.bytesWritten;
+```

recipes/zlib-bytesread-to-byteswritten/README.md

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+schema_version: "1.0"
+name: "@nodejs/zlib-bytesread-to-byteswritten"
+version: 1.0.0
+description: Handle DEP0108 by replacing deprecated `zlib.bytesRead` with `zlib.bytesWritten` in Node.js transform streams
+author: Elie Khoury
+license: MIT
+workflow: workflow.yaml
+category: migration
+
+targets:
+  languages:
+    - javascript
+    - typescript
+
+keywords:
+  - transformation
+  - migration
+  - zlib
+  - bytesRead
+  - bytesWritten
+
+registry:
+  access: public
+  visibility: public

recipes/zlib-bytesread-to-byteswritten/codemod.yaml

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+{
+  "name": "@nodejs/zlib-bytesread-to-byteswritten",
+  "version": "1.0.0",
+  "description": "Replace deprecated `zlib.bytesRead` with `zlib.bytesWritten` in Node.js transform streams",
+  "type": "module",
+  "scripts": {
+    "test": "npx codemod jssg test -l typescript ./src/workflow.ts ./"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/nodejs/userland-migrations.git",
+    "directory": "recipes/zlib-bytesread-to-byteswritten",
+    "bugs": "https://github.com/nodejs/userland-migrations/issues"
+  },
+  "author": "Elie Khoury",
+  "license": "MIT",
+  "homepage": "https://github.com/nodejs/userland-migrations/blob/main/recipes/zlib-bytesread-to-byteswritten/README.md",
+  "devDependencies": {
+    "@codemod.com/jssg-types": "^1.0.9"
+  },
+  "dependencies": {
+    "@nodejs/codemod-utils": "*"
+  }
+}

recipes/zlib-bytesread-to-byteswritten/package.json

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+import { getNodeRequireCalls } from '@nodejs/codemod-utils/ast-grep/require-call';
+import {
+	getNodeImportCalls,
+	getNodeImportStatements,
+} from '@nodejs/codemod-utils/ast-grep/import-statement';
+import { resolveBindingPath } from '@nodejs/codemod-utils/ast-grep/resolve-binding-path';
+import { removeLines } from '@nodejs/codemod-utils/ast-grep/remove-lines';
+import type { Edit, Range, SgRoot } from '@codemod.com/jssg-types/main';
+import type Js from '@codemod.com/jssg-types/langs/javascript';
+
+const ZLIB_FACTORIES = [
+	'createGzip',
+	'createGunzip',
+	'createDeflate',
+	'createInflate',
+	'createBrotliCompress',
+	'createBrotliDecompress',
+	'createUnzip',
+];
+
+const FUNC_KINDS = [
+	'function_declaration',
+	'function_expression',
+	'arrow_function',
+] as const;
+
+export default function transform(root: SgRoot<Js>): string | null {
+	const rootNode = root.root();
+	const edits: Edit[] = [];
+	const linesToRemove: Range[] = [];
+
+	// 1 Find all static and dynamic zlib imports/requires
+	const importNodes = [
+		...getNodeRequireCalls(root, 'node:zlib'),
+		...getNodeImportStatements(root, 'node:zlib'),
+		...getNodeImportCalls(root, 'node:zlib'),
+	];
+
+	const factoryBindings = new Set<string>();
+	const streamVariables: string[] = [];
+
+	// 1.a Resolve all local bindings from "node:zlib"
+	for (const node of importNodes) {
+		for (const factory of ZLIB_FACTORIES) {
+			const binding = resolveBindingPath(node, `$.${factory}`);
+			if (binding) factoryBindings.add(binding);
+		}
+	}
+
+	// If no import is found that means we can skip transformation on this file
+	if (!importNodes.length) return null;
+
+	// 2 Track variables assigned from factories (const, let, var)
+	for (const binding of factoryBindings) {
+		const matches = rootNode.findAll({
+			rule: {
+				kind: 'variable_declarator',
+				has: {
+					field: 'value',
+					kind: 'call_expression',
+					pattern: `${binding}($$$ARGS)`,
+				},
+			},
+		});
+
+		for (const match of matches) {
+			const varMatch = match.field('name');
+
+			if (varMatch) {
+				const varName = varMatch.text();
+				if (!streamVariables.includes(varName)) streamVariables.push(varName);
+			}
+		}
+	}
+
+	// 3 Replace .bytesRead → .bytesWritten for tracked variables
+	for (const variable of streamVariables) {
+		const matches = rootNode.findAll({
+			rule: { pattern: `${variable}.bytesRead` },
+		});
+
+		for (const match of matches) {
+			edits.push(
+				match.replace(match.text().replace('.bytesRead', '.bytesWritten')),
+			);
+		}
+	}
+
+	// Step 4: Replace .bytesRead → .bytesWritten for function parameters
+	for (const kind of FUNC_KINDS) {
+		const funcs = rootNode.findAll({ rule: { kind } });
+
+		for (const func of funcs) {
+			const paramNames = func
+				.field('parameters')
+				?.findAll({ rule: { kind: 'identifier' } });
+
+			for (const paramName of paramNames) {
+				// replace member_expressions that use ${paramName}.bytesRead inside the function context
+				const matches = func.findAll({
+					rule: {
+						kind: 'member_expression',
+						pattern: `${paramName.text()}.bytesRead`,
+					},
+				});
+				for (const match of matches) {
+					edits.push(
+						match.replace(match.text().replace('.bytesRead', '.bytesWritten')),
+					);
+				}
+			}
+		}
+	}
+
+	if (!edits.length) return null;
+
+	return removeLines(rootNode.commitEdits(edits), linesToRemove);
+}

recipes/zlib-bytesread-to-byteswritten/src/workflow.ts

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+const zlib = require("node:zlib");
+const gzip = zlib.createGzip();
+const processed = gzip.bytesWritten;

recipes/zlib-bytesread-to-byteswritten/tests/expected/assigned_bytesRead_variable.js

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+const zlib = require("node:zlib");
+const deflate = zlib.createDeflate();
+deflate.on("finish", () => {
+    const stats = {
+        input: deflate.bytesWritten,
+        output: deflate.bytesWritten
+    };
+});

recipes/zlib-bytesread-to-byteswritten/tests/expected/deflate_finish_stats.js

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+const { createGzip } = require("node:zlib");
+const gzip = createGzip();
+const bytes = gzip.bytesWritten;

recipes/zlib-bytesread-to-byteswritten/tests/expected/destructured_createGzip.js

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+// CommonJS style dynamic import
+async function testCommonJS() {
+    const zlib = await import("node:zlib");
+    const gzip = zlib.createGzip();
+    console.log(gzip.bytesWritten);
+}
+
+async function testCommonJSLet() {
+    let zlib = await import("node:zlib");
+    const gzip = zlib.createGzip();
+    console.log(gzip.bytesWritten);
+}
+
+async function testCommonJSVar() {
+    var zlib = await import("node:zlib");
+    const gzip = zlib.createGzip();
+    console.log(gzip.bytesWritten);
+}
+
+// ESM style dynamic import
+const zlibESM = await import("node:zlib");
+const gzipESM = zlibESM.createGzip();
+console.log(gzipESM.bytesWritten);

recipes/zlib-bytesread-to-byteswritten/tests/expected/dynamic_import.js

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+import { createGzip } from "node:zlib";
+const gzip = createGzip();
+const bytesProcessed = gzip.bytesWritten;