feat(utils): add package.json

Author: AugustinMauroy

package-lock.json

@@ -14,6 +14,7 @@
   "license": "MIT",
   "type": "module",
   "devDependencies": {
+    "@ast-grep/lang-json": "^0.0.4",
     "@ast-grep/napi": "^0.39.3",
     "@codemod.com/jssg-types": "^1.0.3",
     "dedent": "^1.6.0"

utils/package.json

@@ -0,0 +1,159 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import dedent from "dedent";
+import jsonLang from "@ast-grep/lang-json";
+import { registerDynamicLanguage, parse } from "@ast-grep/napi";
+import type { Edit } from "@ast-grep/napi";
+import { getScriptsNode, getNodeJsUsage, replaceNodeJsArgs } from "./package-json.ts";
+
+registerDynamicLanguage({ json: jsonLang });
+
+describe("package-json utilities", () => {
+	describe("getScriptsNode", () => {
+		it("should get the scripts node", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"test": "echo \\"Error: no test specified\\" && exit 1"
+					}
+				}
+			`;
+
+			const result = getScriptsNode(parse('json', input));
+
+			assert(result);
+			assert.strictEqual(result.children().length, 3); // curly braces + pair + curly braces
+		});
+
+		it("should return empty array if any scripts is present", () => {
+			const input = dedent`
+				{
+					"name": "example-package",
+					"version": "1.0.0"
+				}
+			`;
+
+			const result = getNodeJsUsage(parse('json', input));
+
+			assert.strictEqual(result.length, 0);
+		});
+
+		it("should throw an error if multiple scripts nodes are found", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"test": "echo \\"Error: no test specified\\" && exit 1"
+					},
+					"scripts": {
+						"start": "node index.js"
+					}
+				}
+			`;
+
+			assert.throws(() => getScriptsNode(parse('json', input)), {
+				message: /Multiple "scripts" fields found/
+			});
+		});
+	});
+
+	describe("getNodeJsUsage", () => {
+		it("should get Node.js usage in scripts", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "node script.js",
+						"test": "echo \\"Error: no test specified\\" && exit 1"
+					}
+				}
+			`;
+
+			const result = getNodeJsUsage(parse('json', input));
+
+			assert.strictEqual(result.length, 1);
+			assert.strictEqual(result[0].text(), "node script.js");
+		});
+
+		it("should not catch `node_modules`", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "node_modules/.bin/some-tool",
+						"test": "node another-script.js"
+					}
+				}
+			`;
+
+			const result = getNodeJsUsage(parse('json', input));
+
+			assert.strictEqual(result.length, 1);
+			assert.strictEqual(result[0].text(), "node another-script.js");
+		});
+
+		it("should return empty array if no Node.js usage is found", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "npm run build",
+						"test": "echo \\"Error: no test specified\\" && exit 1"
+					}
+				}
+			`;
+
+			const result = getNodeJsUsage(parse('json', input));
+
+			assert.strictEqual(result.length, 0);
+		});
+	});
+
+	describe("replaceNodeJsArgs", () => {
+		it("should replace Node.js arguments in scripts", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "node --experimental-foo script.js",
+					}
+				}
+			`;
+
+			const edits: Edit[] = [];
+			replaceNodeJsArgs(parse('json', input), { '--experimental-foo': '--experimental-bar' }, edits);
+
+			assert.strictEqual(edits.length, 1);
+			assert.strictEqual(edits[0].insertedText, 'node --experimental-bar script.js');
+		});
+
+		it("should not replace an arg that contains same", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "node --experimental-foo-prop script.js",
+					}
+				}
+			`;
+
+			const edits: Edit[] = [];
+			replaceNodeJsArgs(parse('json', input), { '--experimental-foo': '--experimental-bar' }, edits);
+
+			assert.strictEqual(edits.length, 0);
+		});
+
+
+		it("should handle multiple replacements", () => {
+			const input = dedent`
+				{
+					"scripts": {
+						"start": "node --experimental-foo script.js",
+						"test": "node --experimental-foo script.js"
+					}
+				}
+			`;
+
+			const edits: Edit[] = [];
+			replaceNodeJsArgs(parse('json', input), { '--experimental-foo': '--experimental-bar' }, edits);
+
+			assert.strictEqual(edits.length, 2);
+			assert.strictEqual(edits[0].insertedText, 'node --experimental-bar script.js');
+			assert.strictEqual(edits[1].insertedText, 'node --experimental-bar script.js');
+		});
+	});
+});

utils/src/ast-grep/package-json.test.ts

@@ -0,0 +1,78 @@
+import type { SgRoot, Edit } from "@codemod.com/jssg-types/main";
+
+/**
+ * Get the "scripts" node from a package.json AST.
+ * @param packageJsonRootNode The root node of the package.json AST.
+ * @returns The "scripts" node, or null if not found.
+ */
+export const getScriptsNode = (packageJsonRootNode: SgRoot) => {
+    const scriptsNodes = packageJsonRootNode
+        .root()
+        .findAll({
+            rule: {
+				kind: "pair",
+				has: {
+					field: "key",
+					kind: "string",
+					has: {
+						kind: "string_content",
+						regex: "scripts"
+					}
+				}
+            }
+        });
+
+    if (scriptsNodes.length > 1)
+        throw new Error(`Multiple "scripts" fields found in ${packageJsonRootNode.filename()}`);
+
+    return scriptsNodes[0] ?? null;
+};
+
+/**
+ * Get all usage of Node.js in the "scripts" node of a package.json AST.
+ * @param packageJsonRootNode The root node of the package.json AST.
+ * @returns An array of nodes representing the usage of Node.js.
+ */
+export const getNodeJsUsage = (packageJsonRootNode: SgRoot) => {
+	const scriptsNode = getScriptsNode(packageJsonRootNode);
+
+	if (!scriptsNode) return [];
+
+	return scriptsNode
+		.findAll({
+			rule: {
+				kind: "string_content",
+				regex: "\\bnode(\\.exe)?\\b",
+				inside: {
+					kind: "string",
+					inside: {
+						kind: "pair",
+					}
+				}
+			}
+		});
+};
+
+/**
+ * Replace Node.js arguments in the "scripts" node of a package.json AST.
+ * @param packageJsonRootNode The root node of the package.json AST.
+ * @param argsToValues A record mapping arguments to their replacement values.
+ * @param edits An array to collect the edits made.
+ */
+export const replaceNodeJsArgs = (packageJsonRootNode: SgRoot, argsToValues: Record<string, string>, edits: Edit[]) => {
+	const nodeJsUsageNodes = getNodeJsUsage(packageJsonRootNode);
+
+	if (!nodeJsUsageNodes.length) return;
+
+	for (const nodeJsUsageNode of nodeJsUsageNodes) {
+		const text = nodeJsUsageNode.text();
+
+		for (const [argC, argP] of Object.entries(argsToValues)) {
+			const regex = new RegExp(`(?<!\\S)${argC}(?!\\S)`, 'g'); // Match standalone arguments
+			if (regex.test(text)) {
+				const newText = text.replace(regex, argP);
+				edits.push(nodeJsUsageNode.replace(newText));
+			}
+		}
+	}
+};