From 31e075206505da25b37a613a87b3b0e2affc8b0d Mon Sep 17 00:00:00 2001
From: Matt Bierner <matb@microsoft.com>
Date: Tue, 2 Oct 2018 17:04:37 -0700
Subject: [PATCH] Fixing strict null checks in build util

---
 build/lib/util.js | 15 ++++++++-------
 build/lib/util.ts | 21 +++++++++++----------
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/build/lib/util.js b/build/lib/util.js
index dd6f0b56992..904135b508e 100644
--- a/build/lib/util.js
+++ b/build/lib/util.js
@@ -20,13 +20,13 @@ function incremental(streamProvider, initial, supportsCancellation) {
     var output = es.through();
     var state = 'idle';
     var buffer = Object.create(null);
-    var token = !supportsCancellation ? null : { isCancellationRequested: function () { return Object.keys(buffer).length > 0; } };
+    var token = !supportsCancellation ? undefined : { isCancellationRequested: function () { return Object.keys(buffer).length > 0; } };
     var run = function (input, isCancellable) {
         state = 'running';
         var stream = !supportsCancellation ? streamProvider() : streamProvider(isCancellable ? token : NoCancellationToken);
         input
             .pipe(stream)
-            .pipe(es.through(null, function () {
+            .pipe(es.through(undefined, function () {
             state = 'idle';
             eventuallyRun();
         }))
@@ -119,7 +119,7 @@ function loadSourcemaps() {
     var output = input
         .pipe(es.map(function (f, cb) {
         if (f.sourceMap) {
-            cb(null, f);
+            cb(undefined, f);
             return;
         }
         if (!f.contents) {
@@ -128,7 +128,8 @@ function loadSourcemaps() {
         }
         var contents = f.contents.toString('utf8');
         var reg = /\/\/# sourceMappingURL=(.*)$/g;
-        var lastMatch = null, match = null;
+        var lastMatch = null;
+        var match = null;
         while (match = reg.exec(contents)) {
             lastMatch = match;
         }
@@ -140,7 +141,7 @@ function loadSourcemaps() {
                 sources: [f.relative.replace(/\//g, '/')],
                 sourcesContent: [contents]
             };
-            cb(null, f);
+            cb(undefined, f);
             return;
         }
         f.contents = Buffer.from(contents.replace(/\/\/# sourceMappingURL=(.*)$/g, ''), 'utf8');
@@ -149,7 +150,7 @@ function loadSourcemaps() {
                 return cb(err);
             }
             f.sourceMap = JSON.parse(contents);
-            cb(null, f);
+            cb(undefined, f);
         });
     }));
     return es.duplex(input, output);
@@ -192,7 +193,7 @@ function getVersion(root) {
 exports.getVersion = getVersion;
 function rebase(count) {
     return rename(function (f) {
-        var parts = f.dirname.split(/[\/\\]/);
+        var parts = f.dirname ? f.dirname.split(/[\/\\]/) : [];
         f.dirname = parts.slice(count).join(path.sep);
     });
 }
diff --git a/build/lib/util.ts b/build/lib/util.ts
index e1393b86c5b..9ad42b48efc 100644
--- a/build/lib/util.ts
+++ b/build/lib/util.ts
@@ -34,7 +34,7 @@ export function incremental(streamProvider: IStreamProvider, initial: NodeJS.Rea
 	let state = 'idle';
 	let buffer = Object.create(null);
 
-	const token: ICancellationToken = !supportsCancellation ? null : { isCancellationRequested: () => Object.keys(buffer).length > 0 };
+	const token: ICancellationToken | undefined = !supportsCancellation ? undefined : { isCancellationRequested: () => Object.keys(buffer).length > 0 };
 
 	const run = (input, isCancellable) => {
 		state = 'running';
@@ -43,7 +43,7 @@ export function incremental(streamProvider: IStreamProvider, initial: NodeJS.Rea
 
 		input
 			.pipe(stream)
-			.pipe(es.through(null, () => {
+			.pipe(es.through(undefined, () => {
 				state = 'idle';
 				eventuallyRun();
 			}))
@@ -122,7 +122,7 @@ export function toFileUri(filePath: string): string {
 }
 
 export function skipDirectories(): NodeJS.ReadWriteStream {
-	return es.mapSync<VinylFile, VinylFile>(f => {
+	return es.mapSync<VinylFile, VinylFile | undefined>(f => {
 		if (!f.isDirectory()) {
 			return f;
 		}
@@ -157,9 +157,9 @@ export function loadSourcemaps(): NodeJS.ReadWriteStream {
 	const input = es.through();
 
 	const output = input
-		.pipe(es.map<FileSourceMap, FileSourceMap>((f, cb): FileSourceMap => {
+		.pipe(es.map<FileSourceMap, FileSourceMap | undefined>((f, cb): FileSourceMap | undefined => {
 			if (f.sourceMap) {
-				cb(null, f);
+				cb(undefined, f);
 				return;
 			}
 
@@ -171,7 +171,8 @@ export function loadSourcemaps(): NodeJS.ReadWriteStream {
 			const contents = (<Buffer>f.contents).toString('utf8');
 
 			const reg = /\/\/# sourceMappingURL=(.*)$/g;
-			let lastMatch = null, match = null;
+			let lastMatch: RegExpMatchArray | null = null;
+			let match: RegExpMatchArray | null = null;
 
 			while (match = reg.exec(contents)) {
 				lastMatch = match;
@@ -186,7 +187,7 @@ export function loadSourcemaps(): NodeJS.ReadWriteStream {
 					sourcesContent: [contents]
 				};
 
-				cb(null, f);
+				cb(undefined, f);
 				return;
 			}
 
@@ -196,7 +197,7 @@ export function loadSourcemaps(): NodeJS.ReadWriteStream {
 				if (err) { return cb(err); }
 
 				f.sourceMap = JSON.parse(contents);
-				cb(null, f);
+				cb(undefined, f);
 			});
 		}));
 
@@ -236,7 +237,7 @@ export function rimraf(dir: string): (cb: any) => void {
 	return cb => retry(cb);
 }
 
-export function getVersion(root: string): string {
+export function getVersion(root: string): string | undefined {
 	let version = process.env['BUILD_SOURCEVERSION'];
 
 	if (!version || !/^[0-9a-f]{40}$/i.test(version)) {
@@ -248,7 +249,7 @@ export function getVersion(root: string): string {
 
 export function rebase(count: number): NodeJS.ReadWriteStream {
 	return rename(f => {
-		const parts = f.dirname.split(/[\/\\]/);
+		const parts = f.dirname ? f.dirname.split(/[\/\\]/) : [];
 		f.dirname = parts.slice(count).join(path.sep);
 	});
 }