From d231df17b071f74bbcf5b600ee1fbf5152144397 Mon Sep 17 00:00:00 2001
From: Kitson Kelly <me@kitsonkelly.com>
Date: Fri, 13 Sep 2019 07:30:04 +1000
Subject: [PATCH] deno_typescript cleanup/improvements (#2901)

---
 deno_typescript/compiler_main.js | 71 ++++++++++++++++++--------------
 js/compiler.ts                   |  3 +-
 js/diagnostics.ts                |  2 -
 js/ts_global.d.ts                | 14 +++++++
 4 files changed, 55 insertions(+), 35 deletions(-)
 create mode 100644 js/ts_global.d.ts

diff --git a/deno_typescript/compiler_main.js b/deno_typescript/compiler_main.js
index 85e0041173..8288306f3c 100644
--- a/deno_typescript/compiler_main.js
+++ b/deno_typescript/compiler_main.js
@@ -11,6 +11,7 @@ const ASSETS = "$asset$";
  * @param {string} configText
  * @param {Array<string>} rootNames
  */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 function main(configText, rootNames) {
   println(`>>> ts version ${ts.version}`);
   println(`>>> rootNames ${rootNames}`);
@@ -19,22 +20,26 @@ function main(configText, rootNames) {
 
   assert(rootNames.length > 0);
 
-  let { options, diagnostics } = configure(configText);
+  const { options, diagnostics } = configure(configText);
   handleDiagnostics(host, diagnostics);
 
   println(`>>> TS config: ${JSON.stringify(options)}`);
 
   const program = ts.createProgram(rootNames, options, host);
 
-  diagnostics = ts.getPreEmitDiagnostics(program).filter(({ code }) => {
-    // TS2691: An import path cannot end with a '.ts' extension. Consider
-    // importing 'bad-module' instead.
-    if (code === 2691) return false;
-    // TS5009: Cannot find the common subdirectory path for the input files.
-    if (code === 5009) return false;
-    return true;
-  });
-  handleDiagnostics(host, diagnostics);
+  handleDiagnostics(
+    host,
+    ts.getPreEmitDiagnostics(program).filter(({ code }) => {
+      // TS1063: An export assignment cannot be used in a namespace.
+      if (code === 1063) return false;
+      // TS2691: An import path cannot end with a '.ts' extension. Consider
+      // importing 'bad-module' instead.
+      if (code === 2691) return false;
+      // TS5009: Cannot find the common subdirectory path for the input files.
+      if (code === 5009) return false;
+      return true;
+    })
+  );
 
   const emitResult = program.emit();
   handleDiagnostics(host, emitResult.diagnostics);
@@ -102,20 +107,25 @@ const ops = {
 };
 
 /**
+ * This is a minimal implementation of a compiler host to be able to allow the
+ * creation of runtime bundles.  Some of the methods are implemented in a way
+ * to just appease the TypeScript compiler, not to necessarily be a general
+ * purpose implementation.
+ *
  * @implements {ts.CompilerHost}
  */
 class Host {
   /**
-   * @param {string} fileName
+   * @param {string} _fileName
    */
-  fileExists(fileName) {
+  fileExists(_fileName) {
     return true;
   }
 
   /**
-   * @param {string} fileName
+   * @param {string} _fileName
    */
-  readFile(fileName) {
+  readFile(_fileName) {
     unreachable();
     return undefined;
   }
@@ -163,18 +173,17 @@ class Host {
         .replace("/index.d.ts", "");
     }
 
-    let { sourceCode, moduleName } = dispatch("readFile", {
+    const { sourceCode, moduleName } = dispatch("readFile", {
       fileName,
       languageVersion,
       shouldCreateNewSourceFile
     });
 
-    // TODO(ry) A terrible hack. Please remove ASAP.
-    if (fileName.endsWith("typescript.d.ts")) {
-      sourceCode = sourceCode.replace("export = ts;", "");
-    }
-
-    let sourceFile = ts.createSourceFile(fileName, sourceCode, languageVersion);
+    const sourceFile = ts.createSourceFile(
+      fileName,
+      sourceCode,
+      languageVersion
+    );
     sourceFile.moduleName = moduleName;
     return sourceFile;
   }
@@ -201,18 +210,18 @@ class Host {
   }
 
   /**
-   * @param {string} fileName
-   * @param {ts.Path} path
-   * @param {ts.ScriptTarget} languageVersion
-   * @param {*} onError
-   * @param {boolean} shouldCreateNewSourceFile
+   * @param {string} _fileName
+   * @param {ts.Path} _path
+   * @param {ts.ScriptTarget} _languageVersion
+   * @param {*} _onError
+   * @param {boolean} _shouldCreateNewSourceFile
    */
   getSourceFileByPath(
-    fileName,
-    path,
-    languageVersion,
-    onError,
-    shouldCreateNewSourceFile
+    _fileName,
+    _path,
+    _languageVersion,
+    _onError,
+    _shouldCreateNewSourceFile
   ) {
     unreachable();
     return undefined;
diff --git a/js/compiler.ts b/js/compiler.ts
index 12062e63f9..41f23bcd21 100644
--- a/js/compiler.ts
+++ b/js/compiler.ts
@@ -1,9 +1,8 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 // TODO(ry) Combine this implementation with //deno_typescript/compiler_main.js
 
-/// <reference types="../third_party/node_modules/typescript/lib/typescript.d.ts"/>
-
 import "./globals.ts";
+import "./ts_global.d.ts";
 
 import { bold, cyan, yellow } from "./colors.ts";
 import { Console } from "./console.ts";
diff --git a/js/diagnostics.ts b/js/diagnostics.ts
index 5da91483c3..c5377f979b 100644
--- a/js/diagnostics.ts
+++ b/js/diagnostics.ts
@@ -4,8 +4,6 @@
 // compiler, which is strongly influenced by the format of TypeScript
 // diagnostics.
 
-/// <reference types="../third_party/node_modules/typescript/lib/typescript.d.ts"/>
-
 /** The log category for a diagnostic message */
 export enum DiagnosticCategory {
   Log = 0,
diff --git a/js/ts_global.d.ts b/js/ts_global.d.ts
new file mode 100644
index 0000000000..d4b027926c
--- /dev/null
+++ b/js/ts_global.d.ts
@@ -0,0 +1,14 @@
+// Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
+
+// This scopes the `ts` namespace globally, which is where it exists at runtime
+// when building Deno, but the `typescript/lib/typescript.d.ts` is defined as a
+// module.
+
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+import * as ts_ from "../node_modules/typescript/lib/typescript.d.ts";
+
+declare global {
+  namespace ts {
+    export = ts_;
+  }
+}