support presentation.showReuseMessage & clear in task config

packages/task/src/browser/task-schema-updater.ts

@@ -540,7 +540,9 @@ const presentation: IJSONSchema = {
     default: {
         reveal: 'always',
         focus: false,
-        panel: 'shared'
+        panel: 'shared',
+        showReuseMessage: true,
+        clear: false
     },
     description: 'Configures the panel that is used to present the task\'s output and reads its input.',
     additionalProperties: true,
@@ -572,6 +574,16 @@ const presentation: IJSONSchema = {
             ],
             default: 'shared',
             description: 'Controls if the panel is shared between tasks, dedicated to this task or a new one is created on every run.'
+        },
+        showReuseMessage: {
+            type: 'boolean',
+            default: true,
+            description: 'Controls whether to show the "Terminal will be reused by tasks" message.'
+        },
+        clear: {
+            type: 'boolean',
+            default: false,
+            description: 'Controls whether the terminal is cleared before this task is run.'
         }
     }
 };

packages/task/src/browser/task-terminal-widget-manager.ts

@@ -19,7 +19,7 @@ import { ApplicationShell, WidgetOpenerOptions } from '@theia/core/lib/browser';
 import { TerminalWidget } from '@theia/terminal/lib/browser/base/terminal-widget';
 import { TerminalWidgetFactoryOptions } from '@theia/terminal/lib/browser/terminal-widget-impl';
 import { TerminalService } from '@theia/terminal/lib/browser/base/terminal-service';
-import { PanelKind, TaskConfiguration, TaskWatcher, TaskExitedEvent, TaskServer } from '../common';
+import { PanelKind, TaskConfiguration, TaskWatcher, TaskExitedEvent, TaskServer, TaskOutputPresentation } from '../common';
 import { TaskDefinitionRegistry } from './task-definition-registry';
 import { WorkspaceService } from '@theia/workspace/lib/browser/workspace-service';
 
@@ -83,7 +83,8 @@ export class TaskTerminalWidgetManager {
             // find the terminal where the task ran, and mark it as "idle"
             for (const terminal of this.getTaskTerminalWidgets()) {
                 if (terminal.taskId === finishedTaskId) {
-                    this.notifyTaskFinished(terminal);
+                    const showReuseMessage = !!event.config && TaskOutputPresentation.shouldShowReuseMessage(event.config);
+                    this.notifyTaskFinished(terminal, showReuseMessage);
                     break;
                 }
             }
@@ -103,11 +104,11 @@ export class TaskTerminalWidgetManager {
                         terminal.taskConfig = taskConfig;
                         terminal.busy = true;
                     } else {
-                        this.notifyTaskFinished(terminal);
+                        this.notifyTaskFinished(terminal, true);
                     }
                 });
                 const didConnectFailureListener = terminal.onDidOpenFailure(async () => {
-                    this.notifyTaskFinished(terminal);
+                    this.notifyTaskFinished(terminal, true);
                 });
                 terminal.onDidDispose(() => {
                     didConnectListener.dispose();
@@ -127,8 +128,13 @@ export class TaskTerminalWidgetManager {
         if (isNew) {
             this.shell.addWidget(widget, { area: options.widgetOptions ? options.widgetOptions.area : 'bottom' });
             widget.resetTerminal();
-        } else if (options.title) {
-            widget.setTitle(options.title);
+        } else {
+            if (options.title) {
+                widget.setTitle(options.title);
+            }
+            if (options.taskConfig && TaskOutputPresentation.shouldClearTerminalBeforeRun(options.taskConfig)) {
+                widget.clearOutput();
+            }
         }
         this.terminalService.open(widget, options);
 
@@ -178,9 +184,11 @@ export class TaskTerminalWidgetManager {
         return this.terminalService.all.filter(TaskTerminalWidget.is);
     }
 
-    private notifyTaskFinished(terminal: TaskTerminalWidget): void {
+    private notifyTaskFinished(terminal: TaskTerminalWidget, showReuseMessage: boolean): void {
         terminal.busy = false;
         terminal.scrollToBottom();
-        terminal.writeLine('\x1b[1m\n\rTerminal will be reused by tasks. \x1b[0m\n');
+        if (showReuseMessage) {
+            terminal.writeLine('\x1b[1m\n\rTerminal will be reused by tasks. \x1b[0m\n');
+        }
     }
 }

packages/task/src/common/task-protocol.ts

@@ -43,6 +43,8 @@ export interface TaskOutputPresentation {
     focus?: boolean;
     reveal?: RevealKind;
     panel?: PanelKind;
+    showReuseMessage?: boolean;
+    clear?: boolean;
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     [name: string]: any;
 }
@@ -52,7 +54,9 @@ export namespace TaskOutputPresentation {
         let outputPresentation = {
             reveal: RevealKind.Always,
             focus: false,
-            panel: PanelKind.Shared
+            panel: PanelKind.Shared,
+            showReuseMessage: true,
+            clear: false
         };
         if (task && task.presentation) {
             if (task.presentation.reveal) {
@@ -73,10 +77,27 @@ export namespace TaskOutputPresentation {
                 }
                 outputPresentation = { ...outputPresentation, panel };
             }
-            outputPresentation = { ...outputPresentation, focus: !!task.presentation.focus };
+            outputPresentation = {
+                ...outputPresentation,
+                focus: shouldSetFocusToTerminal(task),
+                showReuseMessage: shouldShowReuseMessage(task),
+                clear: shouldClearTerminalBeforeRun(task)
+            };
         }
         return outputPresentation;
     }
+
+    export function shouldSetFocusToTerminal(task: TaskCustomization): boolean {
+        return !!task.presentation && !!task.presentation.focus;
+    }
+
+    export function shouldClearTerminalBeforeRun(task: TaskCustomization): boolean {
+        return !!task.presentation && !!task.presentation.clear;
+    }
+
+    export function shouldShowReuseMessage(task: TaskCustomization): boolean {
+        return !task.presentation || task.presentation.showReuseMessage === undefined || !!task.presentation.showReuseMessage;
+    }
 }
 
 export interface TaskCustomization {