feat(compiler-cli): add support for using TypeScript 4.1 (angular#39571)

clydin · thePunderWoman · commit a7e7c211b51a · 2020-11-25T11:10:00.000-08:00
This change enables projects to be built with TypeScript 4.1. Support for TypeScript 4.0 is also retained. PR Close angular#39571
diff --git a/packages/compiler-cli/src/transformers/program.ts b/packages/compiler-cli/src/transformers/program.ts
@@ -654,7 +654,10 @@ class AngularCompilerProgram implements Program {
     // - we cache all the files in the hostAdapter
     // - new new stubs use the exactly same imports/exports as the old once (we assert that in
     // hostAdapter.updateGeneratedFile).
-    if (tsStructureIsReused(tmpProgram) !== StructureIsReused.Completely) {
+    // TS 4.1+ stores the reuse state in the new program
+    const checkReuseProgram =
+        (ts.versionMajorMinor as string) === '4.0' ? tmpProgram : this._tsProgram;
+    if (tsStructureIsReused(checkReuseProgram) !== StructureIsReused.Completely) {
       throw new Error(`Internal Error: The structure of the program changed during codegen.`);
     }
   }
diff --git a/packages/compiler-cli/src/typescript_support.ts b/packages/compiler-cli/src/typescript_support.ts
@@ -25,7 +25,7 @@ const MIN_TS_VERSION = '4.0.0';
  * Note: this check is disabled in g3, search for
  * `angularCompilerOptions.disableTypeScriptVersionCheck` config param value in g3.
  */
-const MAX_TS_VERSION = '4.1.0';
+const MAX_TS_VERSION = '4.2.0';
 
 /**
  * The currently used version of TypeScript, which can be adjusted for testing purposes using

Original file line number	Diff line number	Diff line change
`@@ -654,7 +654,10 @@ class AngularCompilerProgram implements Program {`
`654`	`654`	`// - we cache all the files in the hostAdapter`
`655`	`655`	`// - new new stubs use the exactly same imports/exports as the old once (we assert that in`
`656`	`656`	`// hostAdapter.updateGeneratedFile).`
`657`		`- if (tsStructureIsReused(tmpProgram) !== StructureIsReused.Completely) {`
	`657`	`+ // TS 4.1+ stores the reuse state in the new program`
	`658`	`+ const checkReuseProgram =`
	`659`	`+ (ts.versionMajorMinor as string) === '4.0' ? tmpProgram : this._tsProgram;`
	`660`	`+ if (tsStructureIsReused(checkReuseProgram) !== StructureIsReused.Completely) {`
`658`	`661`	throw new Error(`Internal Error: The structure of the program changed during codegen.`);
`659`	`662`	`}`
`660`	`663`	`}`