[WIP] TypeScript support in REPL

js/compiler.ts

@@ -405,6 +405,7 @@ export class DenoCompiler
       assert(
         mediaType === MediaType.TypeScript || mediaType === MediaType.JavaScript
       );
+      console.log("pre emit output");
       const output = service.getEmitOutput(fileName);
 
       // Get the relevant diagnostics - this is 3x faster than
@@ -469,6 +470,87 @@ export class DenoCompiler
     return moduleMetaData.outputCode;
   }
 
+  /**
+   * TODO:
+   * Incremental compilation of code used in REPL.
+   */
+  incrementalCompile(
+    sourceCode: SourceCode,
+    previousOutput?: OutputCode
+  ): {
+    define: AmdDefine,
+    diagnostics: ts.Diagnostic[];
+    outputCode: OutputCode;
+    additionalCode: OutputCode;
+  } {
+    const moduleId = "[repl]";
+    const fileName = `${moduleId}.ts`;
+
+    // TODO: this should probably be done only once per REPL
+    // create Module for REPL
+    const moduleMetaData = new ModuleMetaData(
+      moduleId,
+      fileName,
+      MediaType.TypeScript,
+      sourceCode
+    );
+    // TODO: this is poor-boy's cache-buster against TS compiler
+    moduleMetaData.scriptVersion = `${Math.random()}`;
+
+    this._moduleMetaDataMap.set(fileName, moduleMetaData);
+    this._scriptFileNames = [fileName];
+
+    // TODO: temporary solution to be able to resolve modules
+    const define = this._makeDefine(moduleMetaData);
+
+    // TODO: this is mostly copy-pasted from compile()
+    const service = this._service;
+    assert(
+      moduleMetaData.mediaType === MediaType.TypeScript ||
+        moduleMetaData.mediaType === MediaType.JavaScript
+    );
+
+    const output = service.getEmitOutput(fileName);
+
+    // Get the relevant diagnostics - this is 3x faster than
+    // `getPreEmitDiagnostics`.
+    const diagnostics = [
+      // TypeScript is overly opinionated that only CommonJS modules kinds can
+      // support JSON imports.  Allegedly this was fixed in
+      // Microsoft/TypeScript#26825 but that doesn't seem to be working here,
+      // so we will ignore complaints about this compiler setting.
+      ...service
+        .getCompilerOptionsDiagnostics()
+        .filter(diagnostic => diagnostic.code !== 5070),
+      ...service.getSyntacticDiagnostics(fileName),
+      ...service.getSemanticDiagnostics(fileName)
+    ];
+
+    assert(!output.emitSkipped, "The emit was skipped for an unknown reason.");
+
+    assert(
+      output.outputFiles.length === 2,
+      `Expected 2 files to be emitted, got ${output.outputFiles.length}.`
+    );
+
+    const [sourceMapFile, outputFile] = output.outputFiles;
+    moduleMetaData.outputCode = `${outputFile.text}\n//# sourceURL=${fileName}`;
+    moduleMetaData.sourceMap = JSON.parse(sourceMapFile.text);
+
+    moduleMetaData.scriptVersion = "1";
+
+    // TODO:
+    // - diff code with 'previousOutput'
+    // - return only new lines as outputCode
+
+    return {
+      define,
+      diagnostics,
+      outputCode: moduleMetaData.outputCode,
+      additionalCode: ""
+    };
+  }
+
   /** Given a fileName, return what was generated by the compiler. */
   getGeneratedContents = (fileName: string): string | RawSourceMap => {
     this._log("compiler.getGeneratedContents", fileName);

js/repl.ts

@@ -7,6 +7,7 @@ import { close } from "./files";
 import * as dispatch from "./dispatch";
 import { exit } from "./os";
 import { window } from "./globals";
+import { DenoCompiler } from "./compiler";
 
 function startRepl(historyFile: string): number {
   const builder = flatbuffers.createBuilder();
@@ -46,6 +47,20 @@ export function readline(rid: number, prompt: string): string {
   return line || "";
 }
 
+interface ReplContext {
+  lines: string[];
+  previousOutput: string;
+}
+
+/**
+ * Eval helpers.
+ */
+// const EVAL_FILENAME = `[eval].ts`
+const REPL_CONTEXT: ReplContext = {
+  lines: [],
+  previousOutput: ""
+};
+
 // @internal
 export function replLoop(): void {
   window.deno = deno; // FIXME use a new scope (rather than window).
@@ -78,8 +93,28 @@ export function replLoop(): void {
 
 function evaluate(code: string): void {
   try {
-    const result = eval.call(window, code); // FIXME use a new scope.
+    // TODO:
+    // 1. preserve context between calls
+    // 2. run only incremental lines, not full output
+    // 3. output diagnostics
+    REPL_CONTEXT.lines.push(code);
+    const compiledCode = compileReplCode(REPL_CONTEXT);
+
+    console.log("compiledCode", compiledCode);
+
+    if (compiledCode.diagnostics.length > 0) {
+      // TODO: use ts.formatDiagnostic
+      for (const diagnostic of compiledCode.diagnostics) {
+        console.log("[TS diagnostic]", diagnostic.messageText);
+      }
+    }
+
+    window.define = compiledCode.define;
+    // FIXME use a new scope.
+    const result = eval.call(window, compiledCode.outputCode);
     console.log(result);
+    window.define = undefined;
+    REPL_CONTEXT.previousOutput = compiledCode.outputCode;
   } catch (err) {
     if (err instanceof Error) {
       console.error(`${err.constructor.name}: ${err.message}`);
@@ -89,6 +124,15 @@ function evaluate(code: string): void {
   }
 }
 
+const compiler = DenoCompiler.instance();
+
+function compileReplCode(context: ReplContext) {
+  // TODO: right now only last line is passed, we should pass
+  // all lines, and let `incrementalCompile` return only new lines
+  const sourceCode = context.lines[context.lines.length - 1];
+  return compiler.incrementalCompile(sourceCode, context.previousOutput);
+}
+
 function readBlock(
   rid: number,
   prompt: string,