"tsc -b" with minimal watch capabilities

src/compiler/diagnosticMessages.json

@@ -3604,6 +3604,59 @@
         "category": "Error",
         "code": 6309
     },
+    "Project '{0}' is out of date because oldest output '{1}' is older than newest input '{2}'": {
+        "category": "Message",
+        "code": 6350
+    },
+    "Project '{0}' is up to date because newest input '{1}' is older than oldest output '{2}'": {
+        "category": "Message",
+        "code": 6351
+    },
+    "Project '{0}' is out of date because output file '{1}' does not exist": {
+        "category": "Message",
+        "code": 6352
+    },
+
+    "Project '{0}' is up to date with its upstream types": {
+        "category": "Message",
+        "code": 6353
+    },
+    "Sorted list of input projects: {0}": {
+        "category": "Message",
+        "code": 6354
+    },
+    "Would delete the following files:{0}": {
+        "category": "Message",
+        "code": 6355
+    },
+    "Would build project '{0}'": {
+        "category": "Message",
+        "code": 6356
+    },
+    "Building project '{0}'...": {
+        "category": "Message",
+        "code": 6357
+    },
+    "Updating output timestamps of project '{0}'...": {
+        "category": "Message",
+        "code": 6358
+    },
+    "Project '{0}' is up to date because it was previously built": {
+        "category": "Message",
+        "code": 6359
+    },
+    "Project '{0}' is up to date": {
+        "category": "Message",
+        "code": 6360
+    },
+    "Skipping build of project '{0}' because its upstream project '{1}' has errors": {
+        "category": "Message",
+        "code": 6361
+    },
+    "Project '{0}' can't be built because it depends on a project with errors": {
+        "category": "Message",
+        "code": 6362
+    },
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",

src/compiler/program.ts

@@ -189,7 +189,10 @@ namespace ts {
             getEnvironmentVariable: name => sys.getEnvironmentVariable ? sys.getEnvironmentVariable(name) : "",
             getDirectories: (path: string) => sys.getDirectories(path),
             realpath,
-            readDirectory: (path, extensions, include, exclude, depth) => sys.readDirectory(path, extensions, include, exclude, depth)
+            readDirectory: (path, extensions, include, exclude, depth) => sys.readDirectory(path, extensions, include, exclude, depth),
+            getModifiedTime: sys.getModifiedTime && (path => sys.getModifiedTime!(path)),
+            setModifiedTime: sys.setModifiedTime && ((path, date) => sys.setModifiedTime!(path, date)),
+            deleteFile: sys.deleteFile && (path => sys.deleteFile!(path))
         };
     }
 
@@ -2706,7 +2709,7 @@ namespace ts {
     /**
      * Returns the target config filename of a project reference
      */
-    function resolveProjectReferencePath(host: CompilerHost, ref: ProjectReference): string | undefined {
+    export function resolveProjectReferencePath(host: CompilerHost, ref: ProjectReference): string | undefined {
         if (!host.fileExists(ref.path)) {
             return combinePaths(ref.path, "tsconfig.json");
         }

src/compiler/sys.ts

@@ -433,6 +433,7 @@ namespace ts {
         readFile(path: string, encoding?: string): string | undefined;
         getFileSize?(path: string): number;
         writeFile(path: string, data: string, writeByteOrderMark?: boolean): void;
+
         /**
          * @pollingInterval - this parameter is used in polling-based watchers and ignored in watchers that
          * use native OS file watching
@@ -448,6 +449,8 @@ namespace ts {
         getDirectories(path: string): string[];
         readDirectory(path: string, extensions?: ReadonlyArray<string>, exclude?: ReadonlyArray<string>, include?: ReadonlyArray<string>, depth?: number): string[];
         getModifiedTime?(path: string): Date;
+        setModifiedTime?(path: string, time: Date): void;
+        deleteFile?(path: string): void;
         /**
          * A good implementation is node.js' `crypto.createHash`. (https://nodejs.org/api/crypto.html#crypto_crypto_createhash_algorithm)
          */
@@ -592,6 +595,8 @@ namespace ts {
                 },
                 readDirectory,
                 getModifiedTime,
+                setModifiedTime,
+                deleteFile,
                 createHash: _crypto ? createMD5HashUsingNativeCrypto : generateDjb2Hash,
                 createSHA256Hash: _crypto ? createSHA256Hash : undefined,
                 getMemoryUsage() {
@@ -1069,6 +1074,24 @@ namespace ts {
                 }
             }
 
+            function setModifiedTime(path: string, time: Date) {
+                try {
+                    _fs.utimesSync(path, time, time);
+                }
+                catch (e) {
+                    return;
+                }
+            }
+
+            function deleteFile(path: string) {
+                try {
+                    return _fs.unlinkSync(path);
+                }
+                catch (e) {
+                    return;
+                }
+            }
+
             /**
              * djb2 hashing algorithm
              * http://www.cse.yorku.ca/~oz/hash.html