Disables auto-pinning by default (#709)

* Disables auto-pinning by default

* Updates tests

* Updates the README

Author: arcanis

README.md

@@ -286,8 +286,8 @@ same major line. Should you need to upgrade to a new major, use an explicit
   package manager, and to not update the Last Known Good version when it
   downloads a new version of the same major line.
 
-- `COREPACK_ENABLE_AUTO_PIN` can be set to `0` to prevent Corepack from
-  updating the `packageManager` field when it detects that the local package
+- `COREPACK_ENABLE_AUTO_PIN` can be set to `1` to instruct Corepack to
+  update the `packageManager` field when it detects that the local package
   doesn't list it. In general we recommend to always list a `packageManager`
   field (which you can easily set through `corepack use [name]@[version]`), as
   it ensures that your project installs are always deterministic.

sources/Engine.ts

@@ -274,7 +274,7 @@ export class Engine {
           if (typeof locator.reference === `function`)
             fallbackDescriptor.range = await locator.reference();
 
-          if (process.env.COREPACK_ENABLE_AUTO_PIN !== `0`) {
+          if (process.env.COREPACK_ENABLE_AUTO_PIN === `1`) {
             const resolved = await this.resolveDescriptor(fallbackDescriptor, {allowTags: true});
             if (resolved === null)
               throw new UsageError(`Failed to successfully resolve '${fallbackDescriptor.range}' to a valid ${fallbackDescriptor.name} release`);

tests/main.test.ts

@@ -648,7 +648,7 @@ for (const name of SupportedPackageManagerSet) {
 }
 
 describe(`when called on a project without any defined packageManager`, () => {
-  it(`should append the field to package.json by default`, async () => {
+  it(`should not modify package.json by default`, async () => {
     await xfs.mktempPromise(async cwd => {
       await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
       // empty package.json file
@@ -658,14 +658,12 @@ describe(`when called on a project without any defined packageManager`, () => {
 
       const data = await xfs.readJsonPromise(ppath.join(cwd, `package.json` as Filename));
 
-      expect(data).toMatchObject({
-        packageManager: `yarn@${config.definitions.yarn.default}`,
-      });
+      expect(Object.hasOwn(data, `packageManager`)).toBeFalsy();
     });
   });
 
-  it(`should not modify package.json if disabled by env`, async () => {
-    process.env.COREPACK_ENABLE_AUTO_PIN = `0`;
+  it(`should modify package.json if enabled by env`, async () => {
+    process.env.COREPACK_ENABLE_AUTO_PIN = `1`;
 
     await xfs.mktempPromise(async cwd => {
       await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
@@ -676,43 +674,46 @@ describe(`when called on a project without any defined packageManager`, () => {
 
       const data = await xfs.readJsonPromise(ppath.join(cwd, `package.json` as Filename));
 
-      expect(Object.hasOwn(data, `packageManager`)).toBeFalsy();
+      expect(data).toMatchObject({
+        packageManager: expect.stringMatching(/^yarn@/),
+      });
     });
   });
 
-  it(`should not modify package.json if disabled by .corepack.env`, async t => {
+  it(`should modify package.json if enabled by .corepack.env`, async t => {
     // Skip that test on Node.js 18.x as it lacks support for .env files.
     if (process.version.startsWith(`v18.`)) t.skip();
 
     await xfs.mktempPromise(async cwd => {
       await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
         // empty package.json file
       });
-      await xfs.writeFilePromise(ppath.join(cwd, `.corepack.env` as Filename), `COREPACK_ENABLE_AUTO_PIN=0\n`);
+      await xfs.writeFilePromise(ppath.join(cwd, `.corepack.env` as Filename), `COREPACK_ENABLE_AUTO_PIN=1\n`);
 
       await runCli(cwd, [`yarn`]);
 
       const data = await xfs.readJsonPromise(ppath.join(cwd, `package.json` as Filename));
 
-      expect(Object.hasOwn(data, `packageManager`)).toBeFalsy();
+      expect(data).toMatchObject({
+        packageManager: expect.stringMatching(/^yarn@/),
+      });
     });
   });
-  it(`should modify package.json if .corepack.env if disabled`, async () => {
+
+  it(`should not modify package.json if .corepack.env is disabled`, async () => {
     process.env.COREPACK_ENV_FILE = `0`;
 
     await xfs.mktempPromise(async cwd => {
       await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
         // empty package.json file
       });
-      await xfs.writeFilePromise(ppath.join(cwd, `.corepack.env` as Filename), `COREPACK_ENABLE_AUTO_PIN=0\n`);
+      await xfs.writeFilePromise(ppath.join(cwd, `.corepack.env` as Filename), `COREPACK_ENABLE_AUTO_PIN=1\n`);
 
       await runCli(cwd, [`yarn`]);
 
       const data = await xfs.readJsonPromise(ppath.join(cwd, `package.json` as Filename));
 
-      expect(data).toMatchObject({
-        packageManager: `yarn@${config.definitions.yarn.default}`,
-      });
+      expect(Object.hasOwn(data, `packageManager`)).toBeFalsy();
     });
   });
 });
@@ -1302,7 +1303,7 @@ it(`should download latest pnpm from custom registry`, async () => {
     await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
       exitCode: 0,
       stdout: `pnpm: Hello from custom registry\n`,
-      stderr: expect.stringContaining(`! The local project doesn't define a 'packageManager' field. Corepack will now add one referencing [email protected]+sha1.`),
+      stderr: ``,
     });
 
     // Should keep working with cache
@@ -1335,7 +1336,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });
@@ -1358,7 +1359,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });
@@ -1385,7 +1386,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });
@@ -1408,7 +1409,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });
@@ -1434,7 +1435,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });
@@ -1458,7 +1459,7 @@ describe(`should pick up COREPACK_INTEGRITY_KEYS from env`, () => {
       await expect(runCli(cwd, [`pnpm`, `--version`], true)).resolves.toMatchObject({
         exitCode: 0,
         stdout: `pnpm: Hello from custom registry\n`,
-        stderr: expect.stringContaining(`The local project doesn't define a 'packageManager' field`),
+        stderr: ``,
       });
     });
   });