feat: add support for Yarn patch protocol (#887)

Transparently handles the patch protocol version syntax by falling back
to the base version string.

#223
https://yarnpkg.com/cli/patch

Fixes #223

Signed-off-by: Peter Somogyvari <peter.metz@unarin.com>

packages/core/src/package-graph/__tests__/package-graph.spec.ts

@@ -189,6 +189,26 @@ describe('PackageGraph', () => {
       expect(node).toHaveProperty('localDependents', expect.any(Map));
     });
 
+    it('handles yarn patch protocol versions transparently and without hiccups', () => {
+      const pkg = new Package(
+        {
+          name: 'my-pkg',
+          version: '1.0.0',
+          dependencies: {
+            '@ionic-native/splash-screen':
+              'patch:@ionic-native/splash-screen@npm%3A5.36.0#~/.yarn/patches/@ionic-native-splash-screen-npm-5.36.0-531cbbe0f8.patch',
+          },
+        } as unknown as RawManifest,
+        '/path/to/my-pkg'
+      );
+      const node = new PackageGraph([pkg]).get('my-pkg');
+      expect(node?.externalDependencies.get('@ionic-native/splash-screen').rawSpec).toBe('5.36.0');
+      expect(node?.externalDependencies.get('@ionic-native/splash-screen').fetchSpec).toBe('5.36.0');
+      expect(node).toHaveProperty('externalDependencies', expect.any(Map));
+      expect(node).toHaveProperty('localDependencies', expect.any(Map));
+      expect(node).toHaveProperty('localDependents', expect.any(Map));
+    });
+
     it('computes prereleaseId from prerelease version', () => {
       const node = new PackageGraph([new Package({ name: 'my-pkg', version: '1.2.3-rc.4' } as unknown as RawManifest, '/path/to/my-pkg')]).get(
         'my-pkg'

packages/core/src/package-graph/package-graph.ts

@@ -5,6 +5,20 @@ import { Package } from '../package.js';
 import { ValidationError } from '../validation-error.js';
 import { NpaResolveResult } from '../models/index.js';
 
+/**
+ * A regular expression used to capture and substitute package versions (referred to as "spec" in the lerna-lite code).
+ *
+ * An example of what a spec looks like when the yarn patch protocol has been applied to it is this:
+ * `patch:@ionic-native/splash-screen@npm%3A5.36.0#~/.yarn/patches/@ionic-native-splash-screen-npm-5.36.0-531cbbe0f8.patch`
+ *
+ * We extract the original version string of the package from it and continue package graph traversal with that so that
+ * we can finish building the graph in projects where the yarn patch protocol is under use for patching third-party code.
+ *
+ * @see https://github.com/lerna-lite/lerna-lite/issues/223
+ * @see https://yarnpkg.com/cli/patch
+ */
+export const YARN_PATCH_PROTOCOL_REG_EXP = new RegExp(`patch:(.*)@npm%3A(.*)#~\\/.yarn\\/patches\\/(.*).patch`);
+
 /**
  * A graph of packages in the current project.
  *
@@ -68,6 +82,11 @@ export class PackageGraph extends Map<string, PackageGraphNode> {
         // @see https://github.com/yarnpkg/yarn/issues/4212
         let spec = graphDependencies[depName].replace(/^link:/, 'file:');
 
+        // Yarn patch protocol handling: We swap out the patch URL with the regular semantic version.
+        if (spec.startsWith('patch:')) {
+          spec = spec.replace(YARN_PATCH_PROTOCOL_REG_EXP, '$2');
+        }
+
         // npa doesn't support the explicit workspace: protocol, supported by
         // pnpm and Yarn.
         const isWorkspaceSpec = /^workspace:/.test(spec);