Use yaml package instead of @yarnpkg/parsers to manipulate yaml

package.json

@@ -6,21 +6,19 @@
     "@yarnpkg/cli": "^4.8.0",
     "@yarnpkg/core": "^4.3.0",
     "@yarnpkg/fslib": "^3.1.1",
-    "@yarnpkg/parsers": "^3.0.2",
     "@yarnpkg/plugin-essentials": "^4.3.2",
     "@yarnpkg/plugin-git": "^3.1.1",
     "@yarnpkg/plugin-pack": "^4.0.1",
     "chalk": "^5.4.1",
     "clipanion": "^4.0.0-rc.2",
-    "picomatch": "^4.0.2"
+    "picomatch": "^4.0.2",
+    "yaml": "^2.8.1"
   },
   "devDependencies": {
-    "@types/js-yaml": "^4.0.9",
     "@types/node": "^22.0.0",
     "@types/picomatch": "^4",
     "@types/tmp": "^0.2.6",
     "@yarnpkg/builder": "^4.2.0",
-    "js-yaml": "^4.1.0",
     "rimraf": "5.0.0",
     "tmp-promise": "^3.0.3",
     "typescript": "^5.5.2",

sources/__tests__/apply-command.test.ts

@@ -328,4 +328,98 @@ describe("catalogs apply command", () => {
     const yarnrc = await workspace.readYarnrc();
     expect(yarnrc.catalogs).toBeUndefined();
   });
+
+  it("should preserve comments and formatting when updating catalogs", async () => {
+    workspace = await createTestWorkspace();
+
+    const existingYarnrc = await workspace.readYarnrcRaw();
+    await workspace.writeYarnrcRaw(`${existingYarnrc}
+# Yarn configuration
+nodeLinker: node-modules # inline comment
+
+# Registry configuration
+npmRegistryServer: https://registry.npmjs.org
+
+# Catalog configuration
+catalogs:
+  stable:
+    react: npm:17.0.0
+`);
+
+    await workspace.writeCatalogsYml({
+      list: {
+        stable: {
+          react: "npm:18.0.0",
+        },
+      },
+    });
+
+    await workspace.yarn.catalogs.apply();
+
+    const rawContent = await workspace.readYarnrcRaw();
+    expect(rawContent).toContain("# Yarn configuration");
+    expect(rawContent).toContain("# inline comment");
+    expect(rawContent).toContain("# Registry configuration");
+    expect(rawContent).toContain("# Catalog configuration");
+  });
+
+  it("should preserve comments when updating both root and named catalogs", async () => {
+    workspace = await createTestWorkspace();
+
+    const existingYarnrc = await workspace.readYarnrcRaw();
+    await workspace.writeYarnrcRaw(`${existingYarnrc}
+# Root catalog
+catalog:
+  lodash: npm:4.0.0
+
+# Named catalogs
+catalogs:
+  stable:
+    react: npm:17.0.0
+`);
+
+    await workspace.writeCatalogsYml({
+      list: {
+        root: {
+          lodash: "npm:4.17.21",
+        },
+        stable: {
+          react: "npm:18.0.0",
+        },
+      },
+    });
+
+    await workspace.yarn.catalogs.apply();
+
+    const rawContent = await workspace.readYarnrcRaw();
+    expect(rawContent).toContain("# Root catalog");
+    expect(rawContent).toContain("# Named catalogs");
+  });
+
+  it("should preserve comments when removing catalogs", async () => {
+    workspace = await createTestWorkspace();
+
+    const existingYarnrc = await workspace.readYarnrcRaw();
+    await workspace.writeYarnrcRaw(`${existingYarnrc}
+# Config comment
+nodeLinker: node-modules
+
+catalogs:
+  stable:
+    react: npm:18.0.0
+
+# End comment
+`);
+
+    await workspace.writeCatalogsYml({
+      list: {},
+    });
+
+    await workspace.yarn.catalogs.apply();
+
+    const rawContent = await workspace.readYarnrcRaw();
+    expect(rawContent).toContain("# Config comment");
+    expect(rawContent).toContain("# End comment");
+    expect(rawContent).not.toContain("catalogs:");
+  });
 });

sources/__tests__/utils.ts

@@ -1,7 +1,7 @@
 import { execFile } from "node:child_process";
 import { promisify } from "node:util";
 import { type PortablePath, npath, ppath, xfs } from "@yarnpkg/fslib";
-import { dump as yamlDump, load as yamlLoad } from "js-yaml";
+import { parse as yamlParse, stringify as yamlStringify } from "yaml";
 import { dir as tmpDir } from "tmp-promise";
 
 const execFileAsync = promisify(execFile);
@@ -12,7 +12,9 @@ export interface TestWorkspace {
   writeJson: (path: string, content: unknown) => Promise<void>;
   readPackageJson: () => Promise<any>;
   readYarnrc: () => Promise<any>;
+  readYarnrcRaw: () => Promise<string>;
   writeYarnrc: (content: unknown) => Promise<void>;
+  writeYarnrcRaw: (content: string) => Promise<void>;
   writeCatalogsYml: (content: unknown) => Promise<void>;
   yarn: {
     (args: string[]): Promise<{ stdout: string; stderr: string }>;
@@ -76,7 +78,7 @@ export async function createTestWorkspace(): Promise<TestWorkspace> {
       .catch(() => "");
     await xfs.writeFilePromise(
       yarnrcPath,
-      `${existingContent}\n${yamlDump(content)}`,
+      `${existingContent}\n${yamlStringify(content)}`,
     );
   };
 
@@ -85,7 +87,7 @@ export async function createTestWorkspace(): Promise<TestWorkspace> {
       portablePath,
       "catalogs.yml" as PortablePath,
     );
-    await xfs.writeFilePromise(catalogsYmlPath, yamlDump(content));
+    await xfs.writeFilePromise(catalogsYmlPath, yamlStringify(content));
   };
 
   const readPackageJson = async () => {
@@ -97,7 +99,17 @@ export async function createTestWorkspace(): Promise<TestWorkspace> {
   const readYarnrc = async () => {
     const yarnrcPath = ppath.join(portablePath, ".yarnrc.yml" as PortablePath);
     const content = await xfs.readFilePromise(yarnrcPath, "utf8");
-    return yamlLoad(content);
+    return yamlParse(content);
+  };
+
+  const readYarnrcRaw = async () => {
+    const yarnrcPath = ppath.join(portablePath, ".yarnrc.yml" as PortablePath);
+    return await xfs.readFilePromise(yarnrcPath, "utf8");
+  };
+
+  const writeYarnrcRaw = async (content: string) => {
+    const yarnrcPath = ppath.join(portablePath, ".yarnrc.yml" as PortablePath);
+    await xfs.writeFilePromise(yarnrcPath, content);
   };
 
   return {
@@ -106,7 +118,9 @@ export async function createTestWorkspace(): Promise<TestWorkspace> {
     writeJson,
     readPackageJson,
     readYarnrc,
+    readYarnrcRaw,
     writeYarnrc: writeYaml,
+    writeYarnrcRaw,
     writeCatalogsYml,
     yarn,
   };

sources/__tests__/validation.test.ts

@@ -156,7 +156,7 @@ describe("validation", () => {
 
     const { stderr } = await workspace.yarn.add("[email protected]");
     expect(stderr).toContain("react");
-    expect(stderr).toContain("beta, stable");
+    expect(stderr).toContain("stable, beta");
     expect(stderr).toContain("react@catalog:");
   });
 

sources/commands/apply.ts

@@ -1,9 +1,9 @@
 import { BaseCommand } from "@yarnpkg/cli";
 import { Configuration, Project, StreamReport } from "@yarnpkg/core";
 import { type Filename, type PortablePath, ppath, xfs } from "@yarnpkg/fslib";
-import { parseSyml, stringifySyml } from "@yarnpkg/parsers";
 import chalk from "chalk";
 import { Command, Option } from "clipanion";
+import { parseDocument, stringify } from "yaml";
 import { configReader } from "../configuration";
 
 export class ApplyCommand extends BaseCommand {
@@ -140,7 +140,8 @@ export async function readExistingYarnrc(
   }
 
   const content = await xfs.readFilePromise(yarnrcPath, "utf8");
-  return (parseSyml(content) as Record<string, unknown>) || {};
+  const doc = parseDocument(content);
+  return (doc.toJSON() as Record<string, unknown>) || {};
 }
 
 /**
@@ -167,8 +168,8 @@ export function checkForChanges(
     newConfig.catalogs = undefined;
   }
 
-  const oldContent = stringifySyml(existingConfig);
-  const newContent = stringifySyml(newConfig);
+  const oldContent = stringify(existingConfig);
+  const newContent = stringify(newConfig);
 
   return oldContent !== newContent;
 }

sources/configuration/reader.ts

@@ -1,8 +1,8 @@
 import type { Project, Workspace } from "@yarnpkg/core";
 import { structUtils } from "@yarnpkg/core";
 import { type Filename, type PortablePath, ppath, xfs } from "@yarnpkg/fslib";
-import { parseSyml, stringifySyml } from "@yarnpkg/parsers";
 import { isMatch } from "picomatch";
+import { parse, parseDocument } from "yaml";
 import { ROOT_ALIAS_GROUP } from "../constants";
 import { CatalogConfigurationError } from "../errors";
 import type { CatalogsConfiguration } from "./types";
@@ -43,7 +43,7 @@ export class CatalogsConfigurationReader {
     }
 
     const content = await xfs.readFilePromise(catalogsYmlPath, "utf8");
-    const parsed: unknown = parseSyml(content);
+    const parsed: unknown = parse(content);
 
     if (!isValidCatalogsYml(parsed)) {
       throw new CatalogConfigurationError(
@@ -158,26 +158,26 @@ export class CatalogsConfigurationReader {
       ".yarnrc.yml" as Filename as PortablePath,
     );
 
-    let existingConfig: Record<string, unknown> = {};
+    let content = "";
     if (await xfs.existsPromise(yarnrcPath)) {
-      const content = await xfs.readFilePromise(yarnrcPath, "utf8");
-      existingConfig = (parseSyml(content) as Record<string, unknown>) || {};
+      content = await xfs.readFilePromise(yarnrcPath, "utf8");
     }
 
+    const doc = parseDocument(content);
+
     if (catalogs.root && Object.keys(catalogs.root).length > 0) {
-      existingConfig.catalog = catalogs.root;
+      doc.set("catalog", doc.createNode(catalogs.root));
     } else {
-      existingConfig.catalog = undefined;
+      doc.delete("catalog");
     }
 
     if (Object.keys(catalogs.named).length > 0) {
-      existingConfig.catalogs = catalogs.named;
+      doc.set("catalogs", doc.createNode(catalogs.named));
     } else {
-      existingConfig.catalogs = undefined;
+      doc.delete("catalogs");
     }
 
-    const newContent = stringifySyml(existingConfig);
-    await xfs.writeFilePromise(yarnrcPath, newContent);
+    await xfs.writeFilePromise(yarnrcPath, doc.toString());
   }
 
   /**

yarn.lock

@@ -610,13 +610,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@types/js-yaml@npm:^4.0.9":
-  version: 4.0.9
-  resolution: "@types/js-yaml@npm:4.0.9"
-  checksum: 10c0/24de857aa8d61526bbfbbaa383aa538283ad17363fcd5bb5148e2c7f604547db36646440e739d78241ed008702a8920665d1add5618687b6743858fae00da211
-  languageName: node
-  linkType: hard
-
 "@types/keyv@npm:^3.1.4":
   version: 3.1.4
   resolution: "@types/keyv@npm:3.1.4"
@@ -1964,13 +1957,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"argparse@npm:^2.0.1":
-  version: 2.0.1
-  resolution: "argparse@npm:2.0.1"
-  checksum: 10c0/c5640c2d89045371c7cedd6a70212a04e360fd34d6edeae32f6952c63949e3525ea77dbec0289d8213a99bbaeab5abfa860b5c12cf88a2e6cf8106e90dd27a7e
-  languageName: node
-  linkType: hard
-
 "assertion-error@npm:^1.1.0":
   version: 1.1.0
   resolution: "assertion-error@npm:1.1.0"
@@ -3021,17 +3007,6 @@ __metadata:
   languageName: node
   linkType: hard
 
-"js-yaml@npm:^4.1.0":
-  version: 4.1.0
-  resolution: "js-yaml@npm:4.1.0"
-  dependencies:
-    argparse: "npm:^2.0.1"
-  bin:
-    js-yaml: bin/js-yaml.js
-  checksum: 10c0/184a24b4eaacfce40ad9074c64fd42ac83cf74d8c8cd137718d456ced75051229e5061b8633c3366b8aada17945a7a356b337828c19da92b51ae62126575018f
-  languageName: node
-  linkType: hard
-
 "jsbn@npm:1.1.0":
   version: 1.1.0
   resolution: "jsbn@npm:1.1.0"
@@ -4570,30 +4545,37 @@ __metadata:
   languageName: node
   linkType: hard
 
+"yaml@npm:^2.8.1":
+  version: 2.8.1
+  resolution: "yaml@npm:2.8.1"
+  bin:
+    yaml: bin.mjs
+  checksum: 10c0/7c587be00d9303d2ae1566e03bc5bc7fe978ba0d9bf39cc418c3139d37929dfcb93a230d9749f2cb578b6aa5d9ebebc322415e4b653cb83acd8bc0bc321707f3
+  languageName: node
+  linkType: hard
+
 "yarn-plugin-catalogs@workspace:.":
   version: 0.0.0-use.local
   resolution: "yarn-plugin-catalogs@workspace:."
   dependencies:
-    "@types/js-yaml": "npm:^4.0.9"
     "@types/node": "npm:^22.0.0"
     "@types/picomatch": "npm:^4"
     "@types/tmp": "npm:^0.2.6"
     "@yarnpkg/builder": "npm:^4.2.0"
     "@yarnpkg/cli": "npm:^4.8.0"
     "@yarnpkg/core": "npm:^4.3.0"
     "@yarnpkg/fslib": "npm:^3.1.1"
-    "@yarnpkg/parsers": "npm:^3.0.2"
     "@yarnpkg/plugin-essentials": "npm:^4.3.2"
     "@yarnpkg/plugin-git": "npm:^3.1.1"
     "@yarnpkg/plugin-pack": "npm:^4.0.1"
     chalk: "npm:^5.4.1"
     clipanion: "npm:^4.0.0-rc.2"
-    js-yaml: "npm:^4.1.0"
     picomatch: "npm:^4.0.2"
     rimraf: "npm:5.0.0"
     tmp-promise: "npm:^3.0.3"
     typescript: "npm:^5.5.2"
     vitest: "npm:^1.3.1"
+    yaml: "npm:^2.8.1"
   languageName: unknown
   linkType: soft