Rework lint to use tslint-as-a-lib

.vscode/tasks.json

@@ -18,6 +18,25 @@
             "problemMatcher": [
                 "$tsc"
             ]
+        },
+        {
+            "taskName": "lint-server",
+            "args": [],
+            "problemMatcher": {
+                "owner": "typescript",
+                "fileLocation": ["relative", "${workspaceRoot}"],
+                "pattern": {
+                    "regexp": "^(warning|error)\\s+([^(]+)\\s+\\((\\d+|\\d+,\\d+|\\d+,\\d+,\\d+,\\d+)\\):\\s+(.*)$",
+                    "severity": 1,
+                    "file": 2,
+                    "location": 3,
+                    "message": 4
+                },
+				"watchedTaskBeginsRegExp": "^\\*\\*\\*Lint failure\\*\\*\\*$",
+				"watchedTaskEndsRegExp": "^\\*\\*\\* Total \\d+ failures\\.$"
+            },
+            "showOutput": "always",
+            "isWatching": true
         }
     ]
 }

Jakefile.js

@@ -4,6 +4,7 @@ var fs = require("fs");
 var os = require("os");
 var path = require("path");
 var child_process = require("child_process");
+var Linter = require("tslint");
 
 // Variables
 var compilerDirectory = "src/compiler/";
@@ -799,17 +800,85 @@ tslintRulesFiles.forEach(function(ruleFile, i) {
     compileFile(tslintRulesOutFiles[i], [ruleFile], [ruleFile], [], /*useBuiltCompiler*/ true, /*noOutFile*/ true, /*generateDeclarations*/ false, path.join(builtLocalDirectory, "tslint")); 
 });
 
+function getLinterOptions() {
+    return {
+        configuration: require("./tslint.json"),
+        formatter: "prose",
+        formattersDirectory: undefined,
+        rulesDirectory: "built/local/tslint"
+    };
+}
+
+function lintFileContents(options, path, contents) {
+    var ll = new Linter(path, contents, options);
+    return ll.lint();
+}
+
+function lintFile(options, path) {
+    var contents = fs.readFileSync(path, "utf8");
+    return lintFileContents(options, path, contents);
+}
+
+function lintFileAsync(options, path, cb) {
+    fs.readFile(path, "utf8", function(err, contents) {
+        if (err) {
+            return cb(err);
+        }
+        var result = lintFileContents(options, path, contents);
+        cb(undefined, result);
+    });
+}
+
+var lintTargets = compilerSources.concat(harnessCoreSources);
+
 // if the codebase were free of linter errors we could make jake runtests
 // run this task automatically
 desc("Runs tslint on the compiler sources");
 task("lint", ["build-rules"], function() {
-    function success(f) { return function() { console.log('SUCCESS: No linter errors in ' + f + '\n'); }};
-    function failure(f) { return function() { console.log('FAILURE: Please fix linting errors in ' + f + '\n') }};
-
-    var lintTargets = compilerSources.concat(harnessCoreSources);
+    var lintOptions = getLinterOptions();
     for (var i in lintTargets) {
-        var f = lintTargets[i];
-        var cmd = 'tslint --rules-dir built/local/tslint -c tslint.json ' + f;
-        exec(cmd, success(f), failure(f));
+        var result = lintFile(lintOptions, lintTargets[i]);
+        if (result.failureCount > 0) {
+            console.log(result.output);
+        }
     }
-}, { async: true });
+});
+
+var lintSemaphores = {};
+
+function lintWatchFile(filename) {
+    fs.watch(filename, {persistent: true}, function(event) {
+        if (event !== "change") {
+            return;
+        }
+     
+        if (!lintSemaphores[filename]) {
+            lintSemaphores[filename] = true;
+            lintFileAsync(getLinterOptions(), filename, function(err, result) {
+                delete lintSemaphores[filename];
+                if (err) {
+                    console.log(err);
+                    return;
+                }
+                if (result.failureCount > 0) {
+                    console.log("***Lint failure***");
+                    for (var i = 0; i < result.failures.length; i++) {
+                        var failure = result.failures[i];
+                        var s = failure.startPosition.lineAndCharacter;
+                        var e = failure.endPosition.lineAndCharacter;
+                        console.log("warning "+filename+" ("+(s.line+1)+","+(s.character+1)+","+(e.line+1)+","+(e.character+1)+"): "+failure.failure);
+                    }
+                    console.log("*** Total "+result.failureCount+" failures.");
+                }
+            });
+        }
+    });
+}
+
+desc("Watches files for changes to rerun a lint pass");
+task("lint-server", ["build-rules"], function() {
+    console.log('Watching ./src for changes to linted files');
+    for (var i=0; i<lintTargets.length; i++) {
+        lintWatchFile(lintTargets[i]);
+    }
+});