From 50c4ec66871aa7aa24d92f562922de08b9cd045d Mon Sep 17 00:00:00 2001
From: Pete Bacon Darwin <pete@bacondarwin.com>
Date: Mon, 8 Jul 2019 12:43:32 +0100
Subject: [PATCH] fix(ivy): ngcc - resolve path-mapped modules correctly
 (#31450)

Non-wild-card path-mappings were not being matched correctly.

Further path-mapped secondary entry-points that
were imported from the associated primary entry-point were not
being martched correctly.

Fixes #31274

PR Close #31450
---
 .../ngcc/src/dependencies/module_resolver.ts  | 30 +++++++++------
 .../test/dependencies/module_resolver_spec.ts | 38 +++++++++++++++++++
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/packages/compiler-cli/ngcc/src/dependencies/module_resolver.ts b/packages/compiler-cli/ngcc/src/dependencies/module_resolver.ts
index 98cc8e54fa..549690a092 100644
--- a/packages/compiler-cli/ngcc/src/dependencies/module_resolver.ts
+++ b/packages/compiler-cli/ngcc/src/dependencies/module_resolver.ts
@@ -94,14 +94,13 @@ export class ModuleResolver {
       const packagePath = this.findPackagePath(fromPath);
       if (packagePath !== null) {
         for (const mappedPath of mappedPaths) {
-          const isRelative =
-              mappedPath.startsWith(packagePath) && !mappedPath.includes('node_modules');
-          if (isRelative) {
-            return this.resolveAsRelativePath(mappedPath, fromPath);
-          } else if (this.isEntryPoint(mappedPath)) {
+          if (this.isEntryPoint(mappedPath)) {
             return new ResolvedExternalModule(mappedPath);
-          } else if (this.resolveAsRelativePath(mappedPath, fromPath)) {
-            return new ResolvedDeepImport(mappedPath);
+          }
+          const nonEntryPointImport = this.resolveAsRelativePath(mappedPath, fromPath);
+          if (nonEntryPointImport !== null) {
+            return isRelativeImport(packagePath, mappedPath) ? nonEntryPointImport :
+                                                               new ResolvedDeepImport(mappedPath);
           }
         }
       }
@@ -190,7 +189,9 @@ export class ModuleResolver {
       }
     }
 
-    return (bestMapping && bestMatch) ? this.computeMappedTemplates(bestMapping, bestMatch) : [];
+    return (bestMapping !== undefined && bestMatch !== undefined) ?
+        this.computeMappedTemplates(bestMapping, bestMatch) :
+        [];
   }
 
   /**
@@ -203,10 +204,13 @@ export class ModuleResolver {
    */
   private matchMapping(path: string, mapping: ProcessedPathMapping): string|null {
     const {prefix, postfix, hasWildcard} = mapping.matcher;
-    if (path.startsWith(prefix) && path.endsWith(postfix)) {
-      return hasWildcard ? path.substring(prefix.length, path.length - postfix.length) : '';
+    if (hasWildcard) {
+      return (path.startsWith(prefix) && path.endsWith(postfix)) ?
+          path.substring(prefix.length, path.length - postfix.length) :
+          null;
+    } else {
+      return (path === prefix) ? '' : null;
     }
-    return null;
   }
 
   /**
@@ -277,3 +281,7 @@ interface PathMappingPattern {
   postfix: string;
   hasWildcard: boolean;
 }
+
+function isRelativeImport(from: AbsoluteFsPath, to: AbsoluteFsPath) {
+  return to.startsWith(from) && !to.includes('node_modules');
+}
diff --git a/packages/compiler-cli/ngcc/test/dependencies/module_resolver_spec.ts b/packages/compiler-cli/ngcc/test/dependencies/module_resolver_spec.ts
index 452b2a75a4..c88856fa01 100644
--- a/packages/compiler-cli/ngcc/test/dependencies/module_resolver_spec.ts
+++ b/packages/compiler-cli/ngcc/test/dependencies/module_resolver_spec.ts
@@ -43,6 +43,11 @@ runInEachFileSystem(() => {
           name: _('/dist/package-4/sub-folder/index.js'),
           contents: `import {X} from '@shared/package-4/x';`
         },
+        {name: _('/dist/package-4/secondary-entry-point/x.js'), contents: `export class X {}`},
+        {
+          name: _('/dist/package-4/secondary-entry-point/package.json'),
+          contents: 'PACKAGE.JSON for secondary-entry-point'
+        },
         {
           name: _('/dist/sub-folder/package-4/package.json'),
           contents: 'PACKAGE.JSON for package-4'
@@ -199,6 +204,39 @@ runInEachFileSystem(() => {
                      _('/dist/package-4/sub-folder/index.js')))
               .toEqual(new ResolvedExternalModule(_('/dist/sub-folder/package-5/post-fix')));
         });
+
+        it('should resolve primary entry-points if they match non-wildcards exactly', () => {
+          const resolver = new ModuleResolver(
+              getFileSystem(), {baseUrl: '/dist', paths: {'package-4': ['package-4']}});
+          expect(resolver.resolveModuleImport('package-4', _('/libs/local-package/index.js')))
+              .toEqual(new ResolvedExternalModule(_('/dist/package-4')));
+          expect(resolver.resolveModuleImport(
+                     'package-4/secondary-entry-point', _('/libs/local-package/index.js')))
+              .toEqual(null);
+        });
+
+        it('should resolve secondary entry-points if wildcards match', () => {
+          const resolver = new ModuleResolver(getFileSystem(), {
+            baseUrl: '/dist',
+            paths: {'package-4': ['package-4'], 'package-4/*': ['package-4/*']}
+          });
+          expect(resolver.resolveModuleImport('package-4', _('/libs/local-package/index.js')))
+              .toEqual(new ResolvedExternalModule(_('/dist/package-4')));
+          expect(resolver.resolveModuleImport(
+                     'package-4/secondary-entry-point', _('/libs/local-package/index.js')))
+              .toEqual(new ResolvedExternalModule(_('/dist/package-4/secondary-entry-point')));
+        });
+
+        it('should resolve secondary-entry-points referenced from their primary entry-point',
+           () => {
+             const resolver = new ModuleResolver(getFileSystem(), {
+               baseUrl: '/dist',
+               paths: {'package-4': ['package-4'], 'package-4/*': ['package-4/*']}
+             });
+             expect(resolver.resolveModuleImport(
+                        'package-4/secondary-entry-point', _('/dist/package-4/index.js')))
+                 .toEqual(new ResolvedExternalModule(_('/dist/package-4/secondary-entry-point')));
+           });
       });
     });
   });