Adjusted newlines in non-pretty output for consistency

Josh Goldberg · Josh Goldberg · commit bc9ad90a81fc · 2018-04-17T08:28:12.000-07:00
Fixes microsoft#23469
diff --git a/src/compiler/watch.ts b/src/compiler/watch.ts
@@ -44,6 +44,24 @@ namespace ts {
         }
     }
 
+    /** @internal */
+    const screenStartingMessageCodes: number[] = [
+        Diagnostics.Starting_compilation_in_watch_mode.code,
+        Diagnostics.File_change_detected_Starting_incremental_compilation.code,
+    ];
+
+    function getPlainDiagnosticPrecedingNewLines(diagnostic: Diagnostic, newLine: string): string {
+        return contains(screenStartingMessageCodes, diagnostic.code)
+            ? ""
+            : newLine;
+    }
+
+    function getPlainDiagnosticFollowingNewLines(diagnostic: Diagnostic, newLine: string): string {
+        return contains(screenStartingMessageCodes, diagnostic.code)
+            ? newLine + newLine
+            : newLine;
+    }
+
     /**
      * Create a function that reports watch status by writing to the system and handles the formating of the diagnostic
      */
@@ -52,13 +70,13 @@ namespace ts {
             (diagnostic, newLine, options) => {
                 clearScreenIfNotWatchingForFileChanges(system, diagnostic, options);
                 let output = `[${formatColorAndReset(new Date().toLocaleTimeString(), ForegroundColorEscapeSequences.Grey)}] `;
-                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
+                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine}`;
                 system.write(output);
             } :
             (diagnostic, newLine, options) => {
                 clearScreenIfNotWatchingForFileChanges(system, diagnostic, options);
-                let output = new Date().toLocaleTimeString() + " - ";
-                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${newLine + newLine + newLine}`;
+                let output = `${getPlainDiagnosticPrecedingNewLines(diagnostic, newLine)}${new Date().toLocaleTimeString()} - `;
+                output += `${flattenDiagnosticMessageText(diagnostic.messageText, system.newLine)}${getPlainDiagnosticFollowingNewLines(diagnostic, newLine)}`;
                 system.write(output);
             };
     }
