Should not report that files are not part of config for files that are not going to be emitted

Author: sheetalkamat

src/compiler/program.ts

@@ -1008,9 +1008,15 @@ namespace ts {
             return ts.toPath(fileName, currentDirectory, getCanonicalFileName);
         }
 
+        function isValidSourceFileForEmit(file: SourceFile) {
+            // source file is allowed to be emitted and its not source of project reference redirect
+            return sourceFileMayBeEmitted(file, options, isSourceFileFromExternalLibrary, getResolvedProjectReferenceToRedirect) &&
+                !isSourceOfProjectReferenceRedirect(file.fileName);
+        }
+
         function getCommonSourceDirectory() {
             if (commonSourceDirectory === undefined) {
-                const emittedFiles = filter(files, file => sourceFileMayBeEmitted(file, options, isSourceFileFromExternalLibrary, getResolvedProjectReferenceToRedirect));
+                const emittedFiles = filter(files, file => isValidSourceFileForEmit(file));
                 if (options.rootDir && checkSourceFilesBelongToPath(emittedFiles, options.rootDir)) {
                     // If a rootDir is specified use it as the commonSourceDirectory
                     commonSourceDirectory = getNormalizedAbsolutePath(options.rootDir, currentDirectory);
@@ -2933,8 +2939,7 @@ namespace ts {
                 const rootPaths = arrayToSet(rootNames, toPath);
                 for (const file of files) {
                     // Ignore file that is not emitted
-                    if (!sourceFileMayBeEmitted(file, options, isSourceFileFromExternalLibrary, getResolvedProjectReferenceToRedirect)) continue;
-                    if (!rootPaths.has(file.path)) {
+                    if (isValidSourceFileForEmit(file) && !rootPaths.has(file.path)) {
                         addProgramDiagnosticAtRefPath(
                             file,
                             rootPaths,

src/testRunner/unittests/tsserver/projectReferenceErrors.ts

@@ -313,6 +313,7 @@ fnErr();
             const usageConfig: File = {
                 path: `${usageLocation}/tsconfig.json`,
                 content: JSON.stringify({
+                    compilerOptions: { composite: true },
                     references: [{ path: "../dependency" }]
                 })
             };
@@ -381,7 +382,7 @@ fnErr();
             const usageConfig: File = {
                 path: `${usageLocation}/tsconfig.json`,
                 content: JSON.stringify({
-                    compilerOptions: { outFile: "../usage.js" },
+                    compilerOptions: { composite: true, outFile: "../usage.js" },
                     references: [{ path: "../dependency" }]
                 })
             };