fix(@schematics/update): support Angular 6.x when peerDep is 5.x

Fix #10367

Author: hansl

packages/schematics/update/update/index.ts

@@ -7,7 +7,10 @@
  */
 import { logging } from '@angular-devkit/core';
 import {
-  Rule, SchematicContext, SchematicsException, TaskId,
+  Rule,
+  SchematicContext,
+  SchematicsException,
+  TaskId,
   Tree,
 } from '@angular-devkit/schematics';
 import { NodePackageInstallTask, RunSchematicTask } from '@angular-devkit/schematics/tasks';
@@ -19,7 +22,30 @@ import { NpmRepositoryPackageJson } from './npm-package-json';
 import { JsonSchemaForNpmPackageJsonFiles } from './package-json';
 import { UpdateSchema } from './schema';
 
-type VersionRange = string & { __: void; };
+type VersionRange = string & { __VERSION_RANGE: void; };
+type PeerVersionTransform = string | ((range: string) => string);
+
+// This is a map of packageGroupName to range extending function. If it isn't found, the range is
+// kept the same.
+// Angular guarantees that a major is compatible with its following major (so packages that depend
+// on Angular 5 are also compatible with Angular 6). This is, in code, represented by verifying
+// that all other packages that have a peer dependency of `"@angular/core": "^5.0.0"` actually
+// supports 6.0, by adding that compatibility to the range, so it is `^5.0.0 || ^6.0.0`.
+const peerCompatibleWhitelist: { [name: string]: PeerVersionTransform } = {
+  '@angular/core': (range: string) => {
+    range = semver.validRange(range);
+    let major = 1;
+    while (semver.ltr(major + '.0.0', range)) {
+      major++;
+      if (major >= 99) {
+        throw new SchematicsException(`Invalid range: ${JSON.stringify(range)}`);
+      }
+    }
+
+    // Add the major - 1 version as compatible with the angular compatible.
+    return semver.validRange(`^${major + 1}.0.0-rc.0 || ${range}`) || range;
+  },
+};
 
 interface PackageVersionInfo {
   version: VersionRange;
@@ -41,6 +67,30 @@ interface UpdateMetadata {
   migrations?: string;
 }
 
+function _updatePeerVersion(infoMap: Map<string, PackageInfo>, name: string, range: string) {
+  // Resolve packageGroupName.
+  const maybePackageInfo = infoMap.get(name);
+  if (!maybePackageInfo) {
+    return range;
+  }
+  if (maybePackageInfo.target) {
+    name = maybePackageInfo.target.updateMetadata.packageGroup[0] || name;
+  } else {
+    name = maybePackageInfo.installed.updateMetadata.packageGroup[0] || name;
+  }
+
+  const maybeTransform = peerCompatibleWhitelist[name];
+  if (maybeTransform) {
+    if (typeof maybeTransform == 'function') {
+      return maybeTransform(range);
+    } else {
+      return maybeTransform;
+    }
+  }
+
+  return range;
+}
+
 function _validateForwardPeerDependencies(
   name: string,
   infoMap: Map<string, PackageInfo>,
@@ -90,13 +140,16 @@ function _validateReversePeerDependencies(
     installedLogger.debug(`${installed}...`);
     const peers = (installedInfo.target || installedInfo.installed).packageJson.peerDependencies;
 
-    for (const [peer, range] of Object.entries(peers || {})) {
+    for (let [peer, range] of Object.entries(peers || {})) {
       if (peer != name) {
         // Only check peers to the packages we're updating. We don't care about peers
         // that are unmet but we have no effect on.
         continue;
       }
 
+      // Override the peer version range if it's whitelisted.
+      range = _updatePeerVersion(infoMap, peer, range);
+
       if (!semver.satisfies(version, range)) {
         logger.error([
           `Package ${JSON.stringify(installed)} has an incompatible peer dependency to`,

packages/schematics/update/update/index_spec.ts

@@ -88,6 +88,47 @@ describe('@schematics/update', () => {
     ).subscribe(undefined, done.fail, done);
   }, 45000);
 
+  it('updates Angular as compatible with Angular N-1', done => {
+    // Add the basic migration package.
+    const content = virtualFs.fileBufferToString(host.sync.read(normalize('/package.json')));
+    const packageJson = JSON.parse(content);
+    const dependencies = packageJson['dependencies'];
+    dependencies['@angular-devkit-tests/update-peer-dependencies-angular-5'] = '1.0.0';
+    dependencies['@angular/core'] = '5.1.0';
+    dependencies['rxjs'] = '5.5.0';
+    dependencies['zone.js'] = '0.8.26';
+    host.sync.write(
+      normalize('/package.json'),
+      virtualFs.stringToFileBuffer(JSON.stringify(packageJson)),
+    );
+
+    schematicRunner.runSchematicAsync('update', {
+      packages: ['@angular/core'],
+      next: true,
+    }, appTree).pipe(
+      map(tree => {
+        const packageJson = JSON.parse(tree.readContent('/package.json'));
+        expect(packageJson['dependencies']['@angular/core'][0]).toBe('6');
+
+        // Check install task.
+        expect(schematicRunner.tasks).toEqual([
+          {
+            name: 'node-package',
+            options: jasmine.objectContaining({
+              command: 'install',
+            }),
+          },
+          {
+            name: 'run-schematic',
+            options: jasmine.objectContaining({
+              name: 'migrate',
+            }),
+          },
+        ]);
+      }),
+    ).subscribe(undefined, done.fail, done);
+  }, 45000);
+
   it('can migrate only', done => {
     // Add the basic migration package.
     const content = virtualFs.fileBufferToString(host.sync.read(normalize('/package.json')));

tests/schematics/update/packages/update-peer-dependencies-angular-5/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "@angular-devkit-tests/update-peer-dependencies-angular-5",
+  "version": "1.0.0",
+  "description": "Tests",
+  "peerDependencies": {
+    "@angular/core": "^5.0.0"
+  }
+}