From d4c84368e58bf2b3edd49e0d9ca6d08e0d2e6f6c Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Thu, 1 Feb 2018 10:07:28 -0800
Subject: [PATCH] Do not clear console in watch mode if --diagnostics or
 --extendedDiagnostics is specified

---
 src/compiler/watch.ts                         | 37 +++++++-------
 src/harness/unittests/tscWatchMode.ts         | 50 +++++++++++--------
 tests/baselines/reference/api/typescript.d.ts |  4 +-
 3 files changed, 52 insertions(+), 39 deletions(-)

diff --git a/src/compiler/watch.ts b/src/compiler/watch.ts
index 790295c225462..471a9323a3d97 100644
--- a/src/compiler/watch.ts
+++ b/src/compiler/watch.ts
@@ -31,8 +31,11 @@ namespace ts {
         };
     }
 
-    function clearScreenIfNotWatchingForFileChanges(system: System, diagnostic: Diagnostic) {
-        if (system.clearScreen && diagnostic.code !== Diagnostics.Compilation_complete_Watching_for_file_changes.code) {
+    function clearScreenIfNotWatchingForFileChanges(system: System, diagnostic: Diagnostic, options: CompilerOptions) {
+        if (system.clearScreen &&
+            diagnostic.code !== Diagnostics.Compilation_complete_Watching_for_file_changes.code &&
+            !options.extendedDiagnostics &&
+            !options.diagnostics) {
             system.clearScreen();
         }
     }
@@ -42,18 +45,18 @@ namespace ts {
      */
     export function createWatchStatusReporter(system: System, pretty?: boolean): WatchStatusReporter {
         return pretty ?
-        (diagnostic: Diagnostic, newLine: string) => {
-            clearScreenIfNotWatchingForFileChanges(system, diagnostic);
-            let output = `[${ formatColorAndReset(new Date().toLocaleTimeString(), ForegroundColorEscapeSequences.Grey) }] `;
-            output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
-            system.write(output);
-        } :
-        (diagnostic: Diagnostic, newLine: string) => {
-            clearScreenIfNotWatchingForFileChanges(system, diagnostic);
-            let output = new Date().toLocaleTimeString() + " - ";
-            output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
-            system.write(output);
-        };
+            (diagnostic, newLine, options) => {
+                clearScreenIfNotWatchingForFileChanges(system, diagnostic, options);
+                let output = `[${formatColorAndReset(new Date().toLocaleTimeString(), ForegroundColorEscapeSequences.Grey)}] `;
+                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
+                system.write(output);
+            } :
+            (diagnostic, newLine, options) => {
+                clearScreenIfNotWatchingForFileChanges(system, diagnostic, options);
+                let output = new Date().toLocaleTimeString() + " - ";
+                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
+                system.write(output);
+            };
     }
 
     /**
@@ -254,7 +257,7 @@ namespace ts {
 
 namespace ts {
     export type DiagnosticReporter = (diagnostic: Diagnostic) => void;
-    export type WatchStatusReporter = (diagnostic: Diagnostic, newLine: string) => void;
+    export type WatchStatusReporter = (diagnostic: Diagnostic, newLine: string, options: CompilerOptions) => void;
     export type CreateProgram<T extends BuilderProgram> = (rootNames: ReadonlyArray<string>, options: CompilerOptions, host?: CompilerHost, oldProgram?: T) => T;
     export interface WatchCompilerHost<T extends BuilderProgram> {
         /**
@@ -264,7 +267,7 @@ namespace ts {
         /** If provided, callback to invoke after every new program creation */
         afterProgramCreate?(program: T): void;
         /** If provided, called with Diagnostic message that informs about change in watch status */
-        onWatchStatusChange?(diagnostic: Diagnostic, newLine: string): void;
+        onWatchStatusChange?(diagnostic: Diagnostic, newLine: string, options: CompilerOptions): void;
 
         // Only for testing
         /*@internal*/
@@ -725,7 +728,7 @@ namespace ts {
 
         function reportWatchDiagnostic(message: DiagnosticMessage) {
             if (host.onWatchStatusChange) {
-                host.onWatchStatusChange(createCompilerDiagnostic(message), newLine);
+                host.onWatchStatusChange(createCompilerDiagnostic(message), newLine, compilerOptions);
             }
         }
 
diff --git a/src/harness/unittests/tscWatchMode.ts b/src/harness/unittests/tscWatchMode.ts
index 6915a6ad37d8b..b6d3099dc7768 100644
--- a/src/harness/unittests/tscWatchMode.ts
+++ b/src/harness/unittests/tscWatchMode.ts
@@ -2102,35 +2102,45 @@ declare module "fs" {
     });
 
     describe("tsc-watch console clearing", () => {
-        it("clears the console when it starts", () => {
+        function checkConsoleClearing(diagnostics: boolean, extendedDiagnostics: boolean) {
             const file = {
                 path: "f.ts",
                 content: ""
             };
-            const host = createWatchedSystem([file]);
+            const files = [file];
+            const host = createWatchedSystem(files);
+            let clearCount: number | undefined;
+            checkConsoleClears();
 
-            createWatchOfFilesAndCompilerOptions([file.path], host);
-            host.runQueuedTimeoutCallbacks();
+            createWatchOfFilesAndCompilerOptions([file.path], host, { diagnostics, extendedDiagnostics });
+            checkConsoleClears();
 
-            host.checkScreenClears(1);
-        });
+            file.content = "//";
+            host.reloadFS(files);
+            host.runQueuedTimeoutCallbacks();
 
-        it("clears the console on recompile", () => {
-            const file = {
-                path: "f.ts",
-                content: ""
-            };
-            const host = createWatchedSystem([file]);
-            createWatchOfFilesAndCompilerOptions([file.path], host);
+            checkConsoleClears();
 
-            const modifiedFile = {
-                ...file,
-                content: "//"
-            };
-            host.reloadFS([modifiedFile]);
-            host.runQueuedTimeoutCallbacks();
+            function checkConsoleClears() {
+                if (clearCount === undefined) {
+                    clearCount = 0;
+                }
+                else if (!diagnostics && !extendedDiagnostics) {
+                    clearCount++;
+                }
+                host.checkScreenClears(clearCount);
+                return clearCount;
+            }
+        }
 
-            host.checkScreenClears(2);
+        it("without --diagnostics or --extendedDiagnostics", () => {
+            checkConsoleClearing(/*diagnostics*/ false, /*extendedDiagnostics*/ false);
+        });
+        it("with --diagnostics", () => {
+            checkConsoleClearing(/*diagnostics*/ true, /*extendedDiagnostics*/ false);
+        });
+        it("with --extendedDiagnostics", () => {
+            checkConsoleClearing(/*diagnostics*/ false, /*extendedDiagnostics*/ true);
         });
     });
 }
diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
index bdcc29af76e36..6a0a701ca1aea 100644
--- a/tests/baselines/reference/api/typescript.d.ts
+++ b/tests/baselines/reference/api/typescript.d.ts
@@ -3978,7 +3978,7 @@ declare namespace ts {
 }
 declare namespace ts {
     type DiagnosticReporter = (diagnostic: Diagnostic) => void;
-    type WatchStatusReporter = (diagnostic: Diagnostic, newLine: string) => void;
+    type WatchStatusReporter = (diagnostic: Diagnostic, newLine: string, options: CompilerOptions) => void;
     type CreateProgram<T extends BuilderProgram> = (rootNames: ReadonlyArray<string>, options: CompilerOptions, host?: CompilerHost, oldProgram?: T) => T;
     interface WatchCompilerHost<T extends BuilderProgram> {
         /**
@@ -3988,7 +3988,7 @@ declare namespace ts {
         /** If provided, callback to invoke after every new program creation */
         afterProgramCreate?(program: T): void;
         /** If provided, called with Diagnostic message that informs about change in watch status */
-        onWatchStatusChange?(diagnostic: Diagnostic, newLine: string): void;
+        onWatchStatusChange?(diagnostic: Diagnostic, newLine: string, options: CompilerOptions): void;
         useCaseSensitiveFileNames(): boolean;
         getNewLine(): string;
         getCurrentDirectory(): string;