fix(compiler-cli): ensure LogicalFileSystem maintains case in paths

packages/compiler-cli/src/ngtsc/file_system/src/logical.ts

@@ -47,6 +47,12 @@ export class LogicalFileSystem {
    */
   private rootDirs: AbsoluteFsPath[];
 
+  /**
+   * The same root directories as `rootDirs` but with each one converted to its
+   * canonical form for matching in case-insensitive file-systems.
+   */
+  private canonicalRootDirs: AbsoluteFsPath[];
+
   /**
    * A cache of file paths to project paths, because computation of these paths is slightly
    * expensive.
@@ -56,10 +62,9 @@ export class LogicalFileSystem {
   constructor(rootDirs: AbsoluteFsPath[], private compilerHost: ts.CompilerHost) {
     // Make a copy and sort it by length in reverse order (longest first). This speeds up lookups,
     // since there's no need to keep going through the array once a match is found.
-    this.rootDirs =
-        rootDirs.map(dir => this.compilerHost.getCanonicalFileName(dir) as AbsoluteFsPath)
-            .concat([])
-            .sort((a, b) => b.length - a.length);
+    this.rootDirs = rootDirs.concat([]).sort((a, b) => b.length - a.length);
+    this.canonicalRootDirs =
+        this.rootDirs.map(dir => this.compilerHost.getCanonicalFileName(dir) as AbsoluteFsPath);
   }
 
   /**
@@ -83,9 +88,13 @@ export class LogicalFileSystem {
         this.compilerHost.getCanonicalFileName(physicalFile) as AbsoluteFsPath;
     if (!this.cache.has(canonicalFilePath)) {
       let logicalFile: LogicalProjectPath|null = null;
-      for (const rootDir of this.rootDirs) {
-        if (isWithinBasePath(rootDir, canonicalFilePath)) {
-          logicalFile = this.createLogicalProjectPath(canonicalFilePath, rootDir);
+      for (let i = 0; i < this.rootDirs.length; i++) {
+        const rootDir = this.rootDirs[i];
+        const canonicalRootDir = this.canonicalRootDirs[i];
+        if (isWithinBasePath(canonicalRootDir, canonicalFilePath)) {
+          // Note that we match against canonical paths but then create the logical path from
+          // original paths.
+          logicalFile = this.createLogicalProjectPath(physicalFile, rootDir);
           // The logical project does not include any special "node_modules" nested directories.
           if (logicalFile.indexOf('/node_modules/') !== -1) {
             logicalFile = null;

packages/compiler-cli/src/ngtsc/file_system/test/logical_spec.ts

@@ -52,6 +52,24 @@ runInEachFileSystem(() => {
         expect(nonRootFs.logicalPathOfFile(_('/test/foo/foo.ts')))
             .toEqual('/foo/foo' as LogicalProjectPath);
       });
+
+      it('should maintain casing of logical paths', () => {
+        const fs = new LogicalFileSystem([_('/Test')], host);
+        expect(fs.logicalPathOfFile(_('/Test/foo/Foo.ts')))
+            .toEqual('/foo/Foo' as LogicalProjectPath);
+        expect(fs.logicalPathOfFile(_('/Test/bar/bAR.ts')))
+            .toEqual('/bar/bAR' as LogicalProjectPath);
+      });
+
+      it('should use case-sensitivity when matching rootDirs', () => {
+        const fs = new LogicalFileSystem([_('/Test')], host);
+        if (host.useCaseSensitiveFileNames()) {
+          expect(fs.logicalPathOfFile(_('/test/car/CAR.ts'))).toBe(null);
+        } else {
+          expect(fs.logicalPathOfFile(_('/test/car/CAR.ts')))
+              .toEqual('/car/CAR' as LogicalProjectPath);
+        }
+      });
     });
 
     describe('utilities', () => {
@@ -66,6 +84,12 @@ runInEachFileSystem(() => {
             '/foo/index' as LogicalProjectPath, '/bar/index' as LogicalProjectPath);
         expect(res).toEqual('../bar/index');
       });
+
+      it('should maintain casing in relative path between logical files', () => {
+        const res = LogicalProjectPath.relativePathBetween(
+            '/fOO' as LogicalProjectPath, '/bAR' as LogicalProjectPath);
+        expect(res).toEqual('./bAR');
+      });
     });
   });
 });