Adds support for corepack install -g yarn

README.md

@@ -177,7 +177,7 @@ This command doesn't change the global version used when running the package
 manager from outside the project (use the \`-g,--global\` flag if you wish
 to do this).
 
-### `corepack install <-g,--global> [--all] [... name@version]`
+### `corepack install <-g,--global> [--all] [... name[@<version>]]`
 
 | Option                | Description                                |
 | --------------------- | ------------------------------------------ |
@@ -189,7 +189,7 @@ Package managers thus installed will be configured as the new default when
 calling their respective binaries outside of projects defining the
 `packageManager` field.
 
-### `corepack pack [--all] [... name@version]`
+### `corepack pack [--all] [... name[@<version>]]`
 
 | Option                | Description                                |
 | --------------------- | ------------------------------------------ |
@@ -200,7 +200,7 @@ calling their respective binaries outside of projects defining the
 Download the selected package managers and store them inside a tarball
 suitable for use with `corepack install -g`.
 
-### `corepack use <name@version>`
+### `corepack use <name[@<version>]>`
 
 When run, this command will retrieve the latest release matching the provided
 descriptor, assign it to the project's package.json file, and automatically
@@ -215,7 +215,7 @@ 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
 same major line. Should you need to upgrade to a new major, use an explicit
-`corepack use {name}@latest` call.
+`corepack use {name}@latest` call (or simply `corepack use {name}`).
 
 ## Environment Variables
 

sources/specUtils.ts

@@ -11,16 +11,16 @@ export function parseSpec(raw: unknown, source: string, {enforceExactVersion = t
   if (typeof raw !== `string`)
     throw new UsageError(`Invalid package manager specification in ${source}; expected a string`);
 
-  const match = raw.match(/^(?!_)(.+)@(.+)$/);
-  if (match === null || (enforceExactVersion && !semver.valid(match[2])))
-    throw new UsageError(`Invalid package manager specification in ${source}; expected a semver version${enforceExactVersion ? `` : `, range, or tag`}`);
+  const match = raw.match(/^(?!_)([^@]+)(?:@(.+))?$/);
+  if (match === null || (enforceExactVersion && (!match[2] || !semver.valid(match[2]))))
+    throw new UsageError(`Invalid package manager specification in ${source} (${raw}); expected a semver version${enforceExactVersion ? `` : `, range, or tag`}`);
 
   if (!isSupportedPackageManager(match[1]))
     throw new UsageError(`Unsupported package manager specification (${match})`);
 
   return {
     name: match[1],
-    range: match[2],
+    range: match[2] ?? `*`,
   };
 }
 
@@ -57,7 +57,7 @@ export async function findProjectSpec(initialCwd: string, locator: Locator, {tra
       case `NoProject`:
       case `NoSpec`: {
         return fallbackLocator;
-      } break;
+      }
 
       case `Found`: {
         if (result.spec.name !== locator.name) {
@@ -69,7 +69,7 @@ export async function findProjectSpec(initialCwd: string, locator: Locator, {tra
         } else {
           return result.spec;
         }
-      } break;
+      }
     }
   }
 }

tests/main.test.ts

@@ -267,6 +267,25 @@ it(`should allow to call "corepack install -g" with a tag`, async () => {
   });
 });
 
+it(`should allow to call "corepack install -g" without any range`, async () => {
+  await xfs.mktempPromise(async cwd => {
+    await expect(runCli(cwd, [`install`, `-g`, `yarn`])).resolves.toMatchObject({
+      exitCode: 0,
+      stderr: ``,
+    });
+
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      // empty package.json file
+    });
+
+    await expect(runCli(cwd, [`yarn`, `--version`])).resolves.toMatchObject({
+      stdout: expect.not.stringMatching(/^[123]\./),
+      stderr: ``,
+      exitCode: 0,
+    });
+  });
+});
+
 it(`should allow to call "corepack install" without arguments within a configured project`, async () => {
   await xfs.mktempPromise(async cwd => {
     await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {