feat: add limited support for devEngines

README.md

@@ -113,6 +113,35 @@ use in the archive).
 }
 ```
 
+#### `devEngines.packageManager`
+
+When a `devEngines.packageManager` field is defined, and is an object containing
+a `"name"` field (can also optionally contain `version` and `onFail` fields),
+Corepack will use it to validate you're using a compatible package manager.
+
+Depending on the value of `devEngines.packageManager.onFail`:
+
+- if set to `ignore`, Corepack won't print any warning or error.
+- if unset or set to `error`, Corepack will throw an error in case of a mismatch.
+- if set to `warn` or some other value, Corepack will print a warning in case
+  of mismatch.
+
+If the top-level `packageManager` field is missing, Corepack will use the
+package manager defined in `devEngines.packageManager` – in which case you must
+provide a specific version in `devEngines.packageManager.version`, ideally with
+a hash, as explained in the previous section:
+
+```json
+{
+  "devEngines":{
+    "packageManager": {
+      "name": "yarn",
+      "version": "3.2.3+sha224.953c8233f7a92884eee2de69a1b92d1f2ec1655e66d08071ba9a02fa"
+    }
+  }
+}
+```
+
 ## Known Good Releases
 
 When running Corepack within projects that don't list a supported package
@@ -246,6 +275,7 @@ it.
 
 Unlike `corepack use` this command doesn't take a package manager name nor a
 version range, as it will always select the latest available version from the
+range specified in `devEngines.packageManager.version`, or fallback to the
 same major line. Should you need to upgrade to a new major, use an explicit
 `corepack use {name}@latest` call (or simply `corepack use {name}`).
 

sources/commands/Base.ts

@@ -16,10 +16,10 @@ export abstract class BaseCommand extends Command<Context> {
           throw new UsageError(`Couldn't find a project in the local directory - please explicit the package manager to pack, or run this command from a valid project`);
 
         case `NoSpec`:
-          throw new UsageError(`The local project doesn't feature a 'packageManager' field - please explicit the package manager to pack, or update the manifest to reference it`);
+          throw new UsageError(`The local project doesn't feature a 'packageManager' field nor a 'devEngines.packageManager' field - please specify the package manager to pack, or update the manifest to reference it`);
 
         default: {
-          return [lookup.spec];
+          return [lookup.range ?? lookup.spec];
         }
       }
     }

sources/specUtils.ts

@@ -1,7 +1,9 @@
 import {UsageError}                            from 'clipanion';
 import fs                                      from 'fs';
 import path                                    from 'path';
+import semverSatisfies                         from 'semver/functions/satisfies';
 import semverValid                             from 'semver/functions/valid';
+import semverValidRange                        from 'semver/ranges/valid';
 
 import {PreparedPackageManagerInfo}            from './Engine';
 import * as debugUtils                         from './debugUtils';
@@ -52,6 +54,70 @@ export function parseSpec(raw: unknown, source: string, {enforceExactVersion = t
   };
 }
 
+type CorepackPackageJSON = {
+  packageManager?: string;
+  devEngines?: { packageManager?: DevEngineDependency };
+};
+
+interface DevEngineDependency {
+  name: string;
+  version: string;
+  onFail?: 'ignore' | 'warn' | 'error';
+}
+function warnOrThrow(errorMessage: string, onFail?: DevEngineDependency['onFail']) {
+  switch (onFail) {
+    case `ignore`:
+      break;
+    case `error`:
+    case undefined:
+      throw new UsageError(errorMessage);
+    default:
+      console.warn(`! Corepack validation warning: ${errorMessage}`);
+  }
+}
+function parsePackageJSON(packageJSONContent: CorepackPackageJSON) {
+  const {packageManager: pm} = packageJSONContent;
+  if (packageJSONContent.devEngines?.packageManager != null) {
+    const {packageManager} = packageJSONContent.devEngines;
+
+    if (typeof packageManager !== `object`) {
+      console.warn(`! Corepack only supports objects as valid value for devEngines.packageManager. The current value (${JSON.stringify(packageManager)}) will be ignored.`);
+      return pm;
+    }
+    if (Array.isArray(packageManager)) {
+      console.warn(`! Corepack does not currently support array values for devEngines.packageManager`);
+      return pm;
+    }
+
+    const {name, version, onFail} = packageManager;
+    if (typeof name !== `string` || name.includes(`@`)) {
+      warnOrThrow(`The value of devEngines.packageManager.name ${JSON.stringify(name)} is not a supported string value`, onFail);
+      return pm;
+    }
+    if (version != null && (typeof version !== `string` || !semverValidRange(version))) {
+      warnOrThrow(`The value of devEngines.packageManager.version ${JSON.stringify(version)} is not a valid semver range`, onFail);
+      return pm;
+    }
+
+    debugUtils.log(`devEngines.packageManager defines that ${name}@${version} is the local package manager`);
+
+    if (pm) {
+      if (!pm.startsWith?.(`${name}@`))
+        warnOrThrow(`"packageManager" field is set to ${JSON.stringify(pm)} which does not match the "devEngines.packageManager" field set to ${JSON.stringify(name)}`, onFail);
+
+      else if (version != null && !semverSatisfies(pm.slice(packageManager.name.length + 1), version))
+        warnOrThrow(`"packageManager" field is set to ${JSON.stringify(pm)} which does not match the value defined in "devEngines.packageManager" for ${JSON.stringify(name)} of ${JSON.stringify(version)}`, onFail);
+
+      return pm;
+    }
+
+
+    return `${name}@${version ?? `*`}`;
+  }
+
+  return pm;
+}
+
 export async function setLocalPackageManager(cwd: string, info: PreparedPackageManagerInfo) {
   const lookup = await loadSpec(cwd);
 
@@ -75,7 +141,7 @@ export async function setLocalPackageManager(cwd: string, info: PreparedPackageM
 export type LoadSpecResult =
     | {type: `NoProject`, target: string}
     | {type: `NoSpec`, target: string}
-    | {type: `Found`, target: string, spec: Descriptor};
+    | {type: `Found`, target: string, spec: Descriptor, range?: Descriptor};
 
 export async function loadSpec(initialCwd: string): Promise<LoadSpecResult> {
   let nextCwd = initialCwd;
@@ -117,13 +183,20 @@ export async function loadSpec(initialCwd: string): Promise<LoadSpecResult> {
   if (selection === null)
     return {type: `NoProject`, target: path.join(initialCwd, `package.json`)};
 
-  const rawPmSpec = selection.data.packageManager;
+  const rawPmSpec = parsePackageJSON(selection.data);
   if (typeof rawPmSpec === `undefined`)
     return {type: `NoSpec`, target: selection.manifestPath};
 
+  debugUtils.log(`${selection.manifestPath} defines ${rawPmSpec} as local package manager`);
+
+  const spec = parseSpec(rawPmSpec, path.relative(initialCwd, selection.manifestPath));
   return {
     type: `Found`,
     target: selection.manifestPath,
-    spec: parseSpec(rawPmSpec, path.relative(initialCwd, selection.manifestPath)),
+    spec,
+    range: selection.data.devEngines?.packageManager?.version && {
+      name: selection.data.devEngines.packageManager.name,
+      range: selection.data.devEngines.packageManager.version,
+    },
   };
 }

tests/Up.test.ts

@@ -11,24 +11,83 @@ beforeEach(async () => {
 });
 
 describe(`UpCommand`, () => {
-  it(`should upgrade the package manager from the current project`, async () => {
-    await xfs.mktempPromise(async cwd => {
-      await xfs.writeJsonPromise(ppath.join(cwd, `package.json`), {
-        packageManager: `[email protected]`,
-      });
+  describe(`should update the "packageManager" field from the current project`, () => {
+    it(`to the same major if no devEngines range`, async () => {
+      await xfs.mktempPromise(async cwd => {
+        await xfs.writeJsonPromise(ppath.join(cwd, `package.json`), {
+          packageManager: `[email protected]`,
+        });
+
+        await expect(runCli(cwd, [`up`])).resolves.toMatchObject({
+          exitCode: 0,
+          stderr: ``,
+        });
+
+        await expect(xfs.readJsonPromise(ppath.join(cwd, `package.json`))).resolves.toMatchObject({
+          packageManager: `[email protected]+sha512.8dd9fedc5451829619e526c56f42609ad88ae4776d9d3f9456d578ac085115c0c2f0fb02bb7d57fd2e1b6e1ac96efba35e80a20a056668f61c96934f67694fd0`,
+        });
 
-      await expect(runCli(cwd, [`up`])).resolves.toMatchObject({
-        exitCode: 0,
-        stderr: ``,
+        await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+          exitCode: 0,
+          stdout: `2.4.3\n`,
+        });
       });
+    });
+
+    it(`to whichever range devEngines defines`, async () => {
+      await xfs.mktempPromise(async cwd => {
+        await xfs.writeJsonPromise(ppath.join(cwd, `package.json`), {
+          packageManager: `[email protected]`,
+          devEngines: {
+            packageManager: {
+              name: `yarn`,
+              version: `1.x || 2.x`,
+            },
+          },
+        });
+
+        await expect(runCli(cwd, [`up`])).resolves.toMatchObject({
+          exitCode: 0,
+          stderr: ``,
+        });
 
-      await expect(xfs.readJsonPromise(ppath.join(cwd, `package.json`))).resolves.toMatchObject({
-        packageManager: `[email protected]+sha512.8dd9fedc5451829619e526c56f42609ad88ae4776d9d3f9456d578ac085115c0c2f0fb02bb7d57fd2e1b6e1ac96efba35e80a20a056668f61c96934f67694fd0`,
+        await expect(xfs.readJsonPromise(ppath.join(cwd, `package.json`))).resolves.toMatchObject({
+          packageManager: `[email protected]+sha512.8dd9fedc5451829619e526c56f42609ad88ae4776d9d3f9456d578ac085115c0c2f0fb02bb7d57fd2e1b6e1ac96efba35e80a20a056668f61c96934f67694fd0`,
+        });
+
+        await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+          exitCode: 0,
+          stdout: `2.4.3\n`,
+        });
       });
+    });
+
+    it(`to whichever range devEngines defines even if onFail is set to ignore`, async () => {
+      await xfs.mktempPromise(async cwd => {
+        await xfs.writeJsonPromise(ppath.join(cwd, `package.json`), {
+          packageManager: `[email protected]`,
+          devEngines: {
+            packageManager: {
+              name: `yarn`,
+              version: `1.x || 2.x`,
+              onFail: `ignore`,
+            },
+          },
+        });
+
+        await expect(runCli(cwd, [`up`])).resolves.toMatchObject({
+          exitCode: 0,
+          stderr: ``,
+        });
+
+        await expect(xfs.readJsonPromise(ppath.join(cwd, `package.json`))).resolves.toMatchObject({
+          packageManager: `[email protected]+sha512.8dd9fedc5451829619e526c56f42609ad88ae4776d9d3f9456d578ac085115c0c2f0fb02bb7d57fd2e1b6e1ac96efba35e80a20a056668f61c96934f67694fd0`,
+        });
 
-      await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
-        exitCode: 0,
-        stdout: `2.4.3\n`,
+        await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+          exitCode: 0,
+          stdout: `2.4.3\n`,
+        });
       });
     });
   });