fix(jsii): show jsii diagnostics in watch mode and support $tsc problem matcher (#383)

Emit jsii diagnostics error when in watch mode, and also format the errors with a
"TS9999" error code so that VSCode's $tsc problem matcher will show them as
"Problems". Prefix "JSII" in the message to distinguish that these are jsii errors.

Fixes #382

Author: Elad Ben-Israel

packages/jsii/bin/jsii.ts

@@ -1,10 +1,8 @@
 import log4js = require('log4js');
 import path = require('path');
 import process = require('process');
-import ts = require('typescript');
 import yargs = require('yargs');
 import { Compiler, DIAGNOSTICS } from '../lib/compiler';
-import { hasDomain } from '../lib/emitter';
 import { loadProjectInfo } from '../lib/project-info';
 import utils = require('../lib/utils');
 import { VERSION } from '../lib/version';
@@ -33,7 +31,7 @@ import { VERSION } from '../lib/version';
     return { projectRoot, emitResult: await compiler.emit() };
 })().then(({ projectRoot, emitResult }) => {
     for (const diagnostic of emitResult.diagnostics) {
-        _logDiagnostic(diagnostic, projectRoot);
+        utils.logDiagnostic(diagnostic, projectRoot);
     }
     if (emitResult.emitSkipped) {
         process.exit(1);
@@ -72,22 +70,3 @@ function _configureLog4js(verbosity: number) {
         }
     }
 }
-
-function _logDiagnostic(diagnostic: ts.Diagnostic, projectRoot: string) {
-    const formatDiagnosticsHost = {
-        getCurrentDirectory: () => projectRoot,
-        getCanonicalFileName(fileName: string) { return fileName; },
-        getNewLine() { return '\n'; }
-    };
-
-    let message = diagnostic.file
-                ? ts.formatDiagnosticsWithColorAndContext([diagnostic], formatDiagnosticsHost)
-                : ts.formatDiagnostics([diagnostic], formatDiagnosticsHost);
-    if (hasDomain(diagnostic)) {
-        // Make sure error codes don't render as ``TS123``, instead e.g: ``JSII123``.
-        message = message.replace(/([^\w])TS(\d+)([^\w])/, `$1${diagnostic.domain}$2$3`);
-    }
-    const logFunc = utils.diagnosticsLogger(log4js.getLogger(DIAGNOSTICS), diagnostic);
-    if (!logFunc) { return; }
-    logFunc(message.trim());
-}

packages/jsii/lib/assembler.ts

@@ -6,6 +6,7 @@ import spec = require('jsii-spec');
 import log4js = require('log4js');
 import path = require('path');
 import ts = require('typescript');
+import { JSII_DIAGNOSTICS_CODE } from './compiler';
 import { Diagnostic, Emitter } from './emitter';
 import literate = require('./literate');
 import { ProjectInfo } from './project-info';
@@ -223,8 +224,9 @@ export class Assembler implements Emitter {
     private _diagnostic(node: ts.Node | null, category: ts.DiagnosticCategory, messageText: string) {
         this._diagnostics.push({
             domain: 'JSII',
-            category, code: 0,
-            messageText,
+            category,
+            code: JSII_DIAGNOSTICS_CODE,
+            messageText: `JSII: ${messageText}`,
             file: node != null ? node.getSourceFile() : undefined,
             start: node != null ? node.getStart() : undefined,
             length: node != null ? node.getEnd() - node.getStart() : undefined

packages/jsii/lib/compiler.ts

@@ -34,6 +34,7 @@ const COMPILER_OPTIONS: ts.CompilerOptions = {
 
 const LOG = log4js.getLogger('jsii/compiler');
 export const DIAGNOSTICS = 'diagnostics';
+export const JSII_DIAGNOSTICS_CODE = 9999;
 
 export interface CompilerOptions {
     /** The information about the project to be built */
@@ -102,6 +103,7 @@ export class Compiler implements Emitter {
             projectReferences: this.typescriptConfig.references && this.typescriptConfig.references.map(ref => ({ path: path.resolve(ref.path) })),
             host: this.compilerHost
         });
+
         return await this._consumeProgram(prog, this.compilerHost.getDefaultLibLocation());
     }
 
@@ -121,7 +123,12 @@ export class Compiler implements Emitter {
             }
             const orig = host.afterProgramCreate;
             host.afterProgramCreate = async builderProgram => {
-                await this._consumeProgram(builderProgram.getProgram(), host.getDefaultLibLocation!());
+                const emitResult = await this._consumeProgram(builderProgram.getProgram(), host.getDefaultLibLocation!());
+
+                for (const diag of emitResult.diagnostics.filter(d => d.code === JSII_DIAGNOSTICS_CODE)) {
+                    utils.logDiagnostic(diag, projectRoot);
+                }
+
                 if (orig) { orig.call(host, builderProgram); }
             };
             ts.createWatchProgram(host);
@@ -133,13 +140,16 @@ export class Compiler implements Emitter {
         const emit = program.emit();
         if (emit.emitSkipped) {
             LOG.error('Compilation errors prevented the JSII assembly from being created');
-            return emit;
         }
+
+        // we continue to do jsii checker even if there are compilation errors so that
+        // jsii warnings will appear.
         const assembler = new Assembler(this.options.projectInfo, program, stdlib);
         const assmEmit = await assembler.emit();
         if (assmEmit.emitSkipped) {
             LOG.error('Type model errors prevented the JSII assembly from being created');
         }
+
         return {
             emitSkipped: assmEmit.emitSkipped,
             diagnostics: [...emit.diagnostics, ...assmEmit.diagnostics]

packages/jsii/lib/utils.ts

@@ -1,5 +1,6 @@
 import log4js = require('log4js');
 import ts = require('typescript');
+import { DIAGNOSTICS } from './compiler';
 
 /**
  * Obtains the relevant logger to be used for a given diagnostic message.
@@ -24,6 +25,20 @@ export function diagnosticsLogger(logger: log4js.Logger, diagnostic: ts.Diagnost
         return logger.debug.bind(logger);
     }
 }
+export function logDiagnostic(diagnostic: ts.Diagnostic, projectRoot: string) {
+    const formatDiagnosticsHost = {
+        getCurrentDirectory: () => projectRoot,
+        getCanonicalFileName(fileName: string) { return fileName; },
+        getNewLine() { return '\n'; }
+    };
+
+    const message = diagnostic.file
+                ? ts.formatDiagnosticsWithColorAndContext([diagnostic], formatDiagnosticsHost)
+                : ts.formatDiagnostics([diagnostic], formatDiagnosticsHost);
+    const logFunc = diagnosticsLogger(log4js.getLogger(DIAGNOSTICS), diagnostic);
+    if (!logFunc) { return; }
+    logFunc(message.trim());
+}
 
 /**
  * A filter function for ``JSON.stringify`` that removes: