Fix CompilerHost file name resolution (dart-archive#59)

Added error to make it clearer when source file paths are missing from the command line arguments

Updated README

Author: derekxu16

README.md

@@ -1,40 +1,36 @@
 [![Build Status](https://travis-ci.org/dart-lang/js_facade_gen.svg?branch=master)](https://travis-ci.org/dart-lang/js_facade_gen)
 
-Generates `package:js` Javascript interop facades for arbitrary TypeScript
-libraries.
+Generates `package:js` JavaScript interop facades for arbitrary TypeScript libraries.
 
 ## Installation
 
 - [Install Node.js](https://docs.npmjs.com/getting-started/installing-node)
-   - We depend on Node.js so that we can analyze TypeScript files using the [TypeScript language services](https://www.npmjs.com/package/typescript-services) package. This ensures we parse `d.ts` consistently with other tools.
+   - We depend on Node.js so that we can analyze TypeScript files using the [TypeScript Compiler API](https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API) in the [TypeScript](https://www.npmjs.com/package/typescript) package. This ensures we parse `d.ts` consistently with other tools.
 - Execute `npm install -g dart_js_facade_gen` to install.
 
 ## Usage
 
 ### Basic
-`dart_js_facade_gen <input d.ts file>`
+`dart_js_facade_gen <input d.ts file>`<br/>
 Dart interop facade file is written to stdout.
 
 ### Advanced
-`dart_js_facade_gen --destination=<destination-dir> --basePath=<input d.ts file directory> <input d.ts file> <input d.ts file> ...`
+`dart_js_facade_gen --destination=<destination-dir> --base-path=<input d.ts file directory> <input d.ts file> <input d.ts file> ...`
 
 #### Flags
-`--destination=<destination-dir>`: Output generated code to destination-dir
-`--generate-html`: Generate facades for dart:html types rather than importing them
-`--explicit-static`: Disables default assumption that properties declared on the anonymous types of top level variable declarations are static
+`--destination=<destination-dir>`: output generated code to destination-dir<br/>
+`--base-path=<input d.ts file directory>`: specify the directory that contains the input d.ts files<br/>
+`--generate-html`: generate facades for dart:html types rather than importing them<br/>
+`--explicit-static`: disables default assumption that properties declared on the anonymous types of top level variable declarations are static
 
 ### Example
-`dart_js_facade_gen --destination=/usr/foo/tmp/chartjs/lib --basePath=/usr/foo/git/DefinitelyTyped/chartjs /usr/foo/git/DefinitelyTyped/chartjs/chart.d.ts`
-
-## Development
-
-- The Dart SDK must be available to run end to end tests.
+`dart_js_facade_gen --destination=/usr/foo/tmp/chartjs/lib --base-path=/usr/foo/git/DefinitelyTyped/chartjs /usr/foo/git/DefinitelyTyped/chartjs/chart.d.ts`
 
 ### Gulp tasks
 
 - `gulp watch` executes the unit tests in watch mode (use `gulp test.unit` for a single run),
 - `gulp test.check-format` checks the source code formatting using `clang-format`,
-- `gulp test` runs unit tests, e2e tests and checks the source code formatting.
+- `gulp test` runs unit tests and checks the source code formatting.
 
 ### Publish
 

index.js

@@ -6,6 +6,7 @@ var args = require('minimist')(process.argv.slice(2), {
   base: 'string',
   boolean: ['semantic-diagnostics', 'generate-html', 'explicit-static'],
   alias: {
+    'base-path': 'basePath',
     'semantic-diagnostics': 'semanticDiagnostics',
     'generate-html': 'generateHTML',
     'explicit-static': 'explicitStatic'

lib/main.ts

@@ -127,21 +127,22 @@ export class Transpiler {
       this.options.basePath = this.normalizeSlashes(path.resolve(this.options.basePath));
     }
     fileNames = fileNames.map((f) => this.normalizeSlashes(f));
-    let host = this.createCompilerHost();
-    let program = ts.createProgram(fileNames, this.getCompilerOptions(), host);
+    const host = this.createCompilerHost();
+    const program = ts.createProgram(fileNames, this.getCompilerOptions(), host);
     this.fc.setTypeChecker(program.getTypeChecker());
     this.declarationTranspiler.setTypeChecker(program.getTypeChecker());
 
     // Only write files that were explicitly passed in.
     const fileSet = new Set(fileNames);
-    let sourceFiles =
-        program.getSourceFiles().filter((sourceFile) => fileSet.has(sourceFile.fileName));
+    const sourceFiles = program.getSourceFiles().filter((sourceFile) => {
+      return fileSet.has(sourceFile.fileName);
+    });
 
     this.errors = [];
 
-    let sourceFileMap: {[s: string]: ts.SourceFile} = {};
+    const sourceFileMap: Map<string, ts.SourceFile> = new Map();
     sourceFiles.forEach((f: ts.SourceFile) => {
-      sourceFileMap[f.fileName] = f;
+      sourceFileMap.set(f.fileName, f);
     });
 
     // Check for global module export declarations and propogate them to all modules they export.
@@ -154,6 +155,7 @@ export class Transpiler {
         let globalModuleName = base.ident(n.name);
         f.moduleName = globalModuleName;
 
+        const missingFiles: string[] = [];
         f.statements.forEach((e: ts.Node) => {
           if (!ts.isExportDeclaration(e)) return;
           let exportDecl = e;
@@ -164,10 +166,25 @@ export class Transpiler {
               [location], f.fileName, undefined, undefined, this.getCompilerOptions());
           resolvedPath.forEach((p) => {
             if (p.isExternalLibraryImport) return;
-            let exportedFile = sourceFileMap[p.resolvedFileName];
-            exportedFile.moduleName = globalModuleName;
+            const exportedFile = sourceFileMap.get(p.resolvedFileName);
+            if (exportedFile) {
+              exportedFile.moduleName = globalModuleName;
+            } else {
+              missingFiles.push(p.resolvedFileName);
+            }
           });
         });
+        if (missingFiles.length) {
+          const error = new Error();
+          error.message =
+              'The following files were referenced but were not supplied as a command line arguments. Reference the README for usage instructions.';
+          for (const file of missingFiles) {
+            error.message += '\n';
+            error.message += file;
+          }
+          error.name = 'DartFacadeError';
+          throw error;
+        }
       });
     });
 
@@ -215,7 +232,7 @@ export class Transpiler {
 
   private createCompilerHost(): ts.CompilerHost {
     const compilerOptions = this.getCompilerOptions();
-    let compilerHost = ts.createCompilerHost(compilerOptions);
+    const compilerHost = ts.createCompilerHost(compilerOptions);
     let defaultLibFileName = ts.getDefaultLibFileName(compilerOptions);
     defaultLibFileName = this.normalizeSlashes(defaultLibFileName);
     compilerHost.getSourceFile = (sourceName) => {
@@ -232,6 +249,7 @@ export class Transpiler {
     };
     compilerHost.useCaseSensitiveFileNames = () => true;
     compilerHost.getCanonicalFileName = (filename) => filename;
+    compilerHost.getCurrentDirectory = () => '';
     compilerHost.getNewLine = () => '\n';
     compilerHost.resolveModuleNames = getModuleResolver(compilerHost);
 
@@ -339,7 +357,7 @@ export class Transpiler {
     if (diagnosticErrs.length) errors = errors.concat(diagnosticErrs);
 
     if (errors.length) {
-      let e = new Error(errors.join('\n'));
+      const e = new Error(errors.join('\n'));
       e.name = 'DartFacadeError';
       throw e;
     }