microsoft · rbuckton · Jun 16, 2020 · Nov 21, 2019 · Nov 23, 2019 · Dec 9, 2019
diff --git a/.vscode/launch.template.json b/.vscode/launch.template.json
@@ -43,7 +43,7 @@
       },
       "sourceMaps": true,
       "smartStep": true,
-      "preLaunchTask": "tests",
+      "preLaunchTask": "gulp: tests",
       "console": "integratedTerminal",
       "outFiles": [
         "${workspaceRoot}/built/local/run.js"

diff --git a/.vscode/tasks.json b/.vscode/tasks.json
@@ -4,31 +4,42 @@
     "version": "2.0.0",
     "tasks": [
         {
-            "type": "shell",
-            "identifier": "local",
+            "type": "gulp",
             "label": "gulp: local",
-            "command": "gulp",
-            "args": ["local"],
-            "group": { "kind": "build", "isDefault": true },
-            "problemMatcher": ["$gulp-tsc"]
+            "task": "local",
+            "group": {
+                "kind": "build",
+                "isDefault": true
+            },
+            "problemMatcher": [
+                "$tsc"
+            ]
         },
         {
-            "type": "shell",
-            "identifier": "tsc",
+            "type": "gulp",
             "label": "gulp: tsc",
-            "command": "gulp",
-            "args": ["tsc"],
+            "task": "tsc",
             "group": "build",
-            "problemMatcher": ["$gulp-tsc"]
+            "problemMatcher": [
+                "$tsc"
+            ]
         },
         {
-            "type": "shell",
-            "identifier": "tests",
+            "type": "gulp",
             "label": "gulp: tests",
-            "command": "gulp",
-            "args": ["tests"],
+            "task": "tests",
             "group": "build",
-            "problemMatcher": ["$gulp-tsc"]
+            "problemMatcher": [
+                "$tsc"
+            ]
+        },
+        {
+            "type": "gulp",
+            "task": "services",
+            "label": "gulp: services",
+            "problemMatcher": [
+                "$tsc"
+            ],
         }
     ]
 }
diff --git a/src/compat/deprecations.ts b/src/compat/deprecations.ts
diff --git a/src/compat/tsconfig.json b/src/compat/tsconfig.json
@@ -0,0 +1,12 @@
+{
+    "extends": "../tsconfig-base",
+    "compilerOptions": {
+        "outFile": "../../built/local/compat.js"
+    },
+    "references": [
+        { "path": "../compiler" }
+    ],
+    "files": [
+        "deprecations.ts"
+    ]
+}
diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
@@ -1516,6 +1516,20 @@ namespace ts {
         };
     }
 
+    /** A version of `memoize` that supports a single primitive argument */
+    export function memoizeOne<A extends string | number | boolean | undefined, T>(callback: (arg: A) => T): (arg: A) => T {
+        const map = createMap<T>();
+        return (arg: A) => {
+            const key = `${typeof arg}:${arg}`;
+            let value = map.get(key);
+            if (value === undefined && !map.has(key)) {
+                value = callback(arg);
+                map.set(key, value);
+            }
+            return value!;
+        };
+    }
+
     /**
      * High-order function, composes functions. Note that functions are composed inside-out;
      * for example, `compose(a, b)` is the equivalent of `x => b(a(x))`.

diff --git a/src/compiler/corePublic.ts b/src/compiler/corePublic.ts
@@ -79,6 +79,7 @@ namespace ts {
     /** Array that is only intended to be pushed to, never read. */
     export interface Push<T> {
         push(...values: T[]): void;
+        /* @internal*/ readonly length: number;
     }
 
     /* @internal */

diff --git a/src/compiler/debug.ts b/src/compiler/debug.ts
@@ -1,12 +1,72 @@
 /* @internal */
 namespace ts {
+    export enum LogLevel {
+        Off,
+        Error,
+        Warning,
+        Info,
+        Verbose
+    }
+
+    export interface LoggingHost {
+        log(level: LogLevel, s: string): void;
+    }
+
+    export interface DeprecationOptions {
+        message?: string;
+        error?: boolean;
+        since?: Version | string;
+        warnAfter?: Version | string;
+        errorAfter?: Version | string;
+        typeScriptVersion?: Version | string;
+    }
+
     export namespace Debug {
-        let currentAssertionLevel = AssertionLevel.None;
+        let typeScriptVersion: Version | undefined;
 
-        // eslint-disable-next-line prefer-const
+        /* eslint-disable prefer-const */
+        let currentAssertionLevel = AssertionLevel.None;
+        export let currentLogLevel = LogLevel.Warning;
         export let isDebugging = false;
+        export let loggingHost: LoggingHost | undefined;
+        /* eslint-enable prefer-const */
 
         type AssertionKeys = MatchingKeys<typeof Debug, AnyFunction>;
+        export function getTypeScriptVersion() {
+            return typeScriptVersion ?? (typeScriptVersion = new Version(version));
+        }
+
+        export function shouldLog(level: LogLevel): boolean {
+            return currentLogLevel <= level;
+        }
+
+        function logMessage(level: LogLevel, s: string): void {
+            if (loggingHost && shouldLog(level)) {
+                loggingHost.log(level, s);
+            }
+        }
+
+        export function log(s: string): void {
+            logMessage(LogLevel.Info, s);
+        }
+
+        export namespace log {
+            export function error(s: string): void {
+                logMessage(LogLevel.Error, s);
+            }
+
+            export function warn(s: string): void {
+                logMessage(LogLevel.Warning, s);
+            }
+
+            export function log(s: string): void {
+                logMessage(LogLevel.Info, s);
+            }
+
+            export function trace(s: string): void {
+                logMessage(LogLevel.Verbose, s);
+            }
+        }
 
         const assertionCache: Partial<Record<AssertionKeys, { level: AssertionLevel, assertion: AnyFunction }>> = {};
 
@@ -385,7 +445,7 @@ namespace ts {
                                 if (nodeIsSynthesized(this)) return "";
                                 const parseNode = getParseTreeNode(this);
                                 const sourceFile = parseNode && getSourceFileOfNode(parseNode);
-                                return sourceFile ? getSourceTextOfNodeFromSourceFile(sourceFile, parseNode, includeTrivia) : "";
+                                return sourceFile ? getSourceTextOfNodeFromSourceFile(sourceFile, parseNode!, includeTrivia) : "";
                             }
                         }
                     });
@@ -410,5 +470,56 @@ namespace ts {
             isDebugInfoEnabled = true;
         }
 
+        function formatDeprecationMessage(name: string, error: boolean | undefined, errorAfter: Version | undefined, since: Version | undefined, message: string | undefined) {
+            let deprecationMessage = error ? "DeprecationError: " : "DeprecationWarning: ";
+            deprecationMessage += `'${name}' `;
+            deprecationMessage += since ? `has been deprecated since v${since}` : "is deprecated";
+            deprecationMessage += error ? " and can no longer be used." : errorAfter ? ` and will no longer be usable after v${errorAfter}.` : ".";
+            deprecationMessage += message ? ` ${formatStringFromArgs(message, [name], 0)}` : "";
+            return deprecationMessage;
+        }
+
+        function createErrorDeprecation(name: string, errorAfter: Version | undefined, since: Version | undefined, message: string | undefined) {
+            const deprecationMessage = formatDeprecationMessage(name, /*error*/ true, errorAfter, since, message);
+            return () => {
+                throw new TypeError(deprecationMessage);
+            };
+        }
+
+        function createWarningDeprecation(name: string, errorAfter: Version | undefined, since: Version | undefined, message: string | undefined) {
+            let hasWrittenDeprecation = false;
+            return () => {
+                if (!hasWrittenDeprecation) {
+                    log.warn(formatDeprecationMessage(name, /*error*/ false, errorAfter, since, message));
+                    hasWrittenDeprecation = true;
+                }
+            };
+        }
+
+        function createDeprecation(name: string, options: DeprecationOptions & { error: true }): () => never;
+        function createDeprecation(name: string, options?: DeprecationOptions): () => void;
+        function createDeprecation(name: string, options: DeprecationOptions = {}) {
+            const version = typeof options.typeScriptVersion === "string" ? new Version(options.typeScriptVersion) : options.typeScriptVersion ?? getTypeScriptVersion();
+            const errorAfter = typeof options.errorAfter === "string" ? new Version(options.errorAfter) : options.errorAfter;
+            const warnAfter = typeof options.warnAfter === "string" ? new Version(options.warnAfter) : options.warnAfter;
+            const since = typeof options.since === "string" ? new Version(options.since) : options.since ?? warnAfter;
+            const error = options.error || errorAfter && version.compareTo(errorAfter) <= 0;
+            const warn = !warnAfter || version.compareTo(warnAfter) >= 0;
+            return error ? createErrorDeprecation(name, errorAfter, since, options.message) :
+                warn ? createWarningDeprecation(name, errorAfter, since, options.message) :
+                noop;
+        }
+
+        function wrapFunction<F extends (...args: any[]) => any>(deprecation: () => void, func: F): F {
+            return function (this: unknown) {
+                deprecation();
+                return func.apply(this, arguments);
+            } as F;
+        }
+
+        export function deprecate<F extends (...args: any[]) => any>(func: F, options?: DeprecationOptions): F {
+            const deprecation = createDeprecation(getFunctionName(func), options);
+            return wrapFunction(deprecation, func);
+        }
     }
 }
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
@@ -28,7 +28,7 @@ namespace ts {
         if (outFile(options)) {
             const prepends = host.getPrependNodes();
             if (sourceFiles.length || prepends.length) {
-                const bundle = createBundle(sourceFiles, prepends);
+                const bundle = factory.createBundle(sourceFiles, prepends);
                 const result = action(getOutputPathsFor(bundle, host, forceDtsEmit), bundle);
                 if (result) {
                     return result;
@@ -356,7 +356,7 @@ namespace ts {
                 return;
             }
             // Transform the source files
-            const transform = transformNodes(resolver, host, compilerOptions, [sourceFileOrBundle], scriptTransformers, /*allowDtsFiles*/ false);
+            const transform = transformNodes(resolver, host, factory, compilerOptions, [sourceFileOrBundle], scriptTransformers, /*allowDtsFiles*/ false);
 
             const printerOptions: PrinterOptions = {
                 removeComments: compilerOptions.removeComments,
@@ -404,13 +404,13 @@ namespace ts {
             const sourceFiles = isSourceFile(sourceFileOrBundle) ? [sourceFileOrBundle] : sourceFileOrBundle.sourceFiles;
             const filesForEmit = forceDtsEmit ? sourceFiles : filter(sourceFiles, isSourceFileNotJson);
             // Setup and perform the transformation to retrieve declarations from the input files
-            const inputListOrBundle = outFile(compilerOptions) ? [createBundle(filesForEmit, !isSourceFile(sourceFileOrBundle) ? sourceFileOrBundle.prepends : undefined)] : filesForEmit;
+            const inputListOrBundle = outFile(compilerOptions) ? [factory.createBundle(filesForEmit, !isSourceFile(sourceFileOrBundle) ? sourceFileOrBundle.prepends : undefined)] : filesForEmit;
             if (emitOnlyDtsFiles && !getEmitDeclarations(compilerOptions)) {
                 // Checker wont collect the linked aliases since thats only done when declaration is enabled.
                 // Do that here when emitting only dts files
                 filesForEmit.forEach(collectLinkedAliases);
             }
-            const declarationTransform = transformNodes(resolver, host, compilerOptions, inputListOrBundle, declarationTransformers, /*allowDtsFiles*/ false);
+            const declarationTransform = transformNodes(resolver, host, factory, compilerOptions, inputListOrBundle, declarationTransformers, /*allowDtsFiles*/ false);
             if (length(declarationTransform.diagnostics)) {
                 for (const diagnostic of declarationTransform.diagnostics!) {
                     emitterDiagnostics.add(diagnostic);
@@ -680,30 +680,30 @@ namespace ts {
     }
 
     function createSourceFilesFromBundleBuildInfo(bundle: BundleBuildInfo, buildInfoDirectory: string, host: EmitUsingBuildInfoHost): readonly SourceFile[] {
-        const sourceFiles = bundle.sourceFiles.map(fileName => {
-            const sourceFile = createNode(SyntaxKind.SourceFile, 0, 0) as SourceFile;
+        const jsBundle = Debug.checkDefined(bundle.js);
+        const prologueMap = jsBundle.sources?.prologues && arrayToMap(jsBundle.sources.prologues, prologueInfo => "" + prologueInfo.file);
+        return bundle.sourceFiles.map((fileName, index) => {
+            const prologueInfo = prologueMap?.get("" + index);
+            const statements = prologueInfo?.directives.map(directive => {
+                const literal = setTextRange(factory.createStringLiteral(directive.expression.text), directive.expression);
+                const statement = setTextRange(factory.createExpressionStatement(literal), directive);
+                setParent(literal, statement);
+                return statement;
+            });
+            const eofToken = factory.createToken(SyntaxKind.EndOfFileToken);
+            const sourceFile = factory.createSourceFile(statements ?? [], eofToken, NodeFlags.None);
             sourceFile.fileName = getRelativePathFromDirectory(
                 host.getCurrentDirectory(),
                 getNormalizedAbsolutePath(fileName, buildInfoDirectory),
                 !host.useCaseSensitiveFileNames()
             );
-            sourceFile.text = "";
-            sourceFile.statements = createNodeArray();
+            sourceFile.text = prologueInfo?.text ?? "";
+            setTextRangePosWidth(sourceFile, 0, prologueInfo?.text.length ?? 0);
+            setEachParent(sourceFile.statements, sourceFile);
+            setTextRangePosWidth(eofToken, sourceFile.end, 0);
+            setParent(eofToken, sourceFile);
             return sourceFile;
         });
-        const jsBundle = Debug.checkDefined(bundle.js);
-        forEach(jsBundle.sources && jsBundle.sources.prologues, prologueInfo => {
-            const sourceFile = sourceFiles[prologueInfo.file];
-            sourceFile.text = prologueInfo.text;
-            sourceFile.end = prologueInfo.text.length;
-            sourceFile.statements = createNodeArray(prologueInfo.directives.map(directive => {
-                const statement = createNode(SyntaxKind.ExpressionStatement, directive.pos, directive.end) as PrologueDirective;
-                statement.expression = createNode(SyntaxKind.StringLiteral, directive.expression.pos, directive.expression.end) as StringLiteral;
-                statement.expression.text = directive.expression.text;
-                return statement;
-            }));
-        });
-        return sourceFiles;
     }
 
     /*@internal*/
@@ -2292,7 +2292,7 @@ namespace ts {
 
         function emitPropertyAccessExpression(node: PropertyAccessExpression) {
             const expression = cast(emitExpression(node.expression), isExpression);
-            const token = node.questionDotToken || createNode(SyntaxKind.DotToken, node.expression.end, node.name.pos) as DotToken;
+            const token = node.questionDotToken || setTextRangePosEnd(factory.createToken(SyntaxKind.DotToken) as DotToken, node.expression.end, node.name.pos);
             const linesBeforeDot = getLinesBetweenNodes(node, node.expression, token);
             const linesAfterDot = getLinesBetweenNodes(node, token, node.name);
 
@@ -3559,15 +3559,15 @@ namespace ts {
         }
 
         function emitJSDocTypeLiteral(lit: JSDocTypeLiteral) {
-            emitList(lit, createNodeArray(lit.jsDocPropertyTags), ListFormat.JSDocComment);
+            emitList(lit, factory.createNodeArray(lit.jsDocPropertyTags), ListFormat.JSDocComment);
         }
 
         function emitJSDocSignature(sig: JSDocSignature) {
             if (sig.typeParameters) {
-                emitList(sig, createNodeArray(sig.typeParameters), ListFormat.JSDocComment);
+                emitList(sig, factory.createNodeArray(sig.typeParameters), ListFormat.JSDocComment);
             }
             if (sig.parameters) {
-                emitList(sig, createNodeArray(sig.parameters), ListFormat.JSDocComment);
+                emitList(sig, factory.createNodeArray(sig.parameters), ListFormat.JSDocComment);
             }
             if (sig.type) {
                 writeLine();