fix(compiler): Update types for TypeScript nullability support

packages/compiler-cli/src/compiler_host.ts

@@ -33,7 +33,7 @@ export class CompilerHost implements AotCompilerHost {
   private resolverCache = new Map<string, ModuleMetadata[]>();
   private bundleIndexCache = new Map<string, boolean>();
   private bundleIndexNames = new Set<string>();
-  private moduleFileNames = new Map<string, string>();
+  private moduleFileNames = new Map<string, string|null>();
   protected resolveModuleNameHost: CompilerHostContext;
 
   constructor(
@@ -71,7 +71,7 @@ export class CompilerHost implements AotCompilerHost {
 
   moduleNameToFileName(m: string, containingFile: string): string|null {
     const key = m + ':' + (containingFile || '');
-    let result = this.moduleFileNames.get(key);
+    let result: string|null = this.moduleFileNames.get(key) || null;
     if (!result) {
       if (!containingFile || !containingFile.length) {
         if (m.indexOf('.') === 0) {
@@ -183,7 +183,7 @@ export class CompilerHost implements AotCompilerHost {
     return sf;
   }
 
-  getMetadataFor(filePath: string): ModuleMetadata[] {
+  getMetadataFor(filePath: string): ModuleMetadata[]|undefined {
     if (!this.context.fileExists(filePath)) {
       // If the file doesn't exists then we cannot return metadata for the file.
       // This will occur if the user refernced a declared module for which no file
@@ -263,6 +263,7 @@ export class CompilerHost implements AotCompilerHost {
     if (this.context.fileExists(filePath)) {
       return this.context.readFile(filePath);
     }
+    return null;
   }
 
   getOutputFileName(sourceFilePath: string): string {
@@ -287,7 +288,7 @@ export class CompilerHost implements AotCompilerHost {
 
   calculateEmitPath(filePath: string): string {
     // Write codegen in a directory structure matching the sources.
-    let root = this.options.basePath;
+    let root = this.options.basePath !;
     for (const eachRootDir of this.options.rootDirs || []) {
       if (this.options.trace) {
         console.error(`Check if ${filePath} is under rootDirs element ${eachRootDir}`);
@@ -373,7 +374,7 @@ export class ModuleResolutionHostAdapter extends CompilerHostContextAdapter impl
   constructor(private host: ts.ModuleResolutionHost) {
     super();
     if (host.directoryExists) {
-      this.directoryExists = (directoryName: string) => host.directoryExists(directoryName);
+      this.directoryExists = (directoryName: string) => host.directoryExists !(directoryName);
     }
   }
 

packages/compiler-cli/src/extract_i18n.ts

@@ -23,7 +23,7 @@ function extract(
     ngOptions: tsc.AngularCompilerOptions, cliOptions: tsc.I18nExtractionCliOptions,
     program: ts.Program, host: ts.CompilerHost): Promise<void> {
   return Extractor.create(ngOptions, program, host, cliOptions.locale)
-      .extract(cliOptions.i18nFormat, cliOptions.outFile);
+      .extract(cliOptions.i18nFormat !, cliOptions.outFile);
 }
 
 // Entry point

packages/compiler-cli/src/ngtools_api.ts

@@ -92,9 +92,9 @@ export class NgTools_InternalApi_NG_2 {
     const hostContext: CompilerHostContext =
         new CustomLoaderModuleResolutionHostAdapter(options.readResource, options.host);
     const cliOptions: NgcCliOptions = {
-      i18nFormat: options.i18nFormat,
-      i18nFile: options.i18nFile,
-      locale: options.locale,
+      i18nFormat: options.i18nFormat !,
+      i18nFile: options.i18nFile !,
+      locale: options.locale !,
       basePath: options.basePath
     };
 
@@ -148,6 +148,6 @@ export class NgTools_InternalApi_NG_2 {
     const extractor = Extractor.create(
         options.angularCompilerOptions, options.program, options.host, locale, hostContext);
 
-    return extractor.extract(options.i18nFormat, options.outFile || null);
+    return extractor.extract(options.i18nFormat !, options.outFile || null);
   }
 }

packages/compiler-cli/src/ngtools_impl.ts

@@ -33,7 +33,8 @@ export type LazyRouteMap = {
 // A route definition. Normally the short form 'path/to/module#ModuleClassName' is used by
 // the user, and this is a helper class to extract information from it.
 export class RouteDef {
-  private constructor(public readonly path: string, public readonly className: string = null) {}
+  private constructor(public readonly path: string, public readonly className: string|null = null) {
+  }
 
   toString() {
     return (this.className === null || this.className == 'default') ?
@@ -58,7 +59,7 @@ export function listLazyRoutesOfModule(
   const entryRouteDef = RouteDef.fromString(entryModule);
   const containingFile = _resolveModule(entryRouteDef.path, entryRouteDef.path, host);
   const modulePath = `./${containingFile.replace(/^(.*)\//, '')}`;
-  const className = entryRouteDef.className;
+  const className = entryRouteDef.className !;
 
   // List loadChildren of this single module.
   const appStaticSymbol = reflector.findDeclaration(modulePath, className, containingFile);

packages/compiler-cli/src/path_mapped_compiler_host.ts

@@ -40,7 +40,7 @@ export class PathMappedCompilerHost extends CompilerHost {
     return fileName;
   }
 
-  moduleNameToFileName(m: string, containingFile: string) {
+  moduleNameToFileName(m: string, containingFile: string): string|null {
     if (!containingFile || !containingFile.length) {
       if (m.indexOf('.') === 0) {
         throw new Error('Resolution of relative paths requires a containing file.');
@@ -59,6 +59,7 @@ export class PathMappedCompilerHost extends CompilerHost {
         return this.getCanonicalFileName(resolved.resolvedFileName);
       }
     }
+    return null;
   }
 
   /**
@@ -90,7 +91,7 @@ export class PathMappedCompilerHost extends CompilerHost {
 
     const importModuleName = importedFile.replace(EXT, '');
     const parts = importModuleName.split(path.sep).filter(p => !!p);
-    let foundRelativeImport: string;
+    let foundRelativeImport: string = undefined !;
     for (let index = parts.length - 1; index >= 0; index--) {
       let candidate = parts.slice(index, parts.length).join(path.sep);
       if (resolvable(candidate)) {
@@ -135,5 +136,6 @@ export class PathMappedCompilerHost extends CompilerHost {
         return metadata ? [metadata] : [];
       }
     }
+    return null !;
   }
 }

packages/compiler-cli/tsconfig-build.json

@@ -4,6 +4,7 @@
     "declaration": true,
     "experimentalDecorators": true,
     "noImplicitAny": true,
+    "strictNullChecks": true,
     "module": "commonjs",
     "outDir": "../../dist/packages/compiler-cli",
     "paths": {