feat(compiler-cli): Check unvalidated combination of ngc and TypeScript (#22293)

closes #20669

PR Close #22293

packages/compiler-cli/src/ngtools_api2.ts

@@ -60,6 +60,7 @@ export interface CompilerOptions extends ts.CompilerOptions {
   i18nInFile?: string;
   i18nInMissingTranslations?: 'error'|'warning'|'ignore';
   preserveWhitespaces?: boolean;
+  disableTypeScriptVersionCheck?: boolean;
 }
 
 export interface CompilerHost extends ts.CompilerHost {

packages/compiler-cli/src/transformers/api.ts

@@ -132,6 +132,9 @@ export interface CompilerOptions extends ts.CompilerOptions {
   // position.
   disableExpressionLowering?: boolean;
 
+  // Disable TypeScript Version Check.
+  disableTypeScriptVersionCheck?: boolean;
+
   // Locale of the application
   i18nOutLocale?: string;
   // Export format (xlf, xlf2 or xmb)

packages/compiler-cli/src/transformers/program.ts

@@ -71,10 +71,11 @@ class AngularCompilerProgram implements Program {
       rootNames: ReadonlyArray<string>, private options: CompilerOptions,
       private host: CompilerHost, oldProgram?: Program) {
     this.rootNames = [...rootNames];
-    const [major, minor] = ts.version.split('.');
 
-    Number(major) > 2 || (Number(major) === 2 && Number(minor) >= 4) ||
-        userError('The Angular Compiler requires TypeScript >= 2.4.');
+    if (ts.version < '2.4.2' || (ts.version >= '2.7.0' && !options.disableTypeScriptVersionCheck)) {
+      throw new Error(
+          `The Angular Compiler requires TypeScript >=2.4.2 and <2.7 but ${ts.version} was found instead.`);
+    }
 
     this.oldTsProgram = oldProgram ? oldProgram.getTsProgram() : undefined;
     if (oldProgram) {