Make diff gutter decorators width configurable

src/vs/workbench/parts/scm/electron-browser/dirtydiffDecorator.ts

@@ -1104,8 +1104,18 @@ export class DirtyDiffWorkbenchController implements ext.IWorkbenchContribution,
 		@IConfigurationService private configurationService: IConfigurationService
 	) {
 		const onDidChangeConfiguration = filterEvent(configurationService.onDidChangeConfiguration, e => e.affectsConfiguration('scm.diffDecorations'));
+		const onDidChangeDiffWidthConfiguration = filterEvent(configurationService.onDidChangeConfiguration, e => e.affectsConfiguration('scm.diffGutterWidth'));
+
 		onDidChangeConfiguration(this.onDidChangeConfiguration, this, this.disposables);
 		this.onDidChangeConfiguration();
+
+		const diffWidthStyle = document.createElement('style');
+		diffWidthStyle.className = 'diff-width-style';
+		diffWidthStyle.type = 'text/css';
+		document.head.appendChild(diffWidthStyle);
+
+		onDidChangeDiffWidthConfiguration(this.onDidChangeDiffWidthConfiguration, this);
+		this.onDidChangeDiffWidthConfiguration();
 	}
 
 	private onDidChangeConfiguration(): void {
@@ -1118,6 +1128,24 @@ export class DirtyDiffWorkbenchController implements ext.IWorkbenchContribution,
 		}
 	}
 
+	private onDidChangeDiffWidthConfiguration(): void {
+		let width = this.configurationService.getValue<number>('scm.diffGutterWidth');
+
+		if (isNaN(width) || width <= 0 || width > 5) {
+			width = 3;
+		}
+
+		const diffWidthStyle = document.head.getElementsByClassName('diff-width-style')[0];
+
+		if (diffWidthStyle) {
+			diffWidthStyle.innerHTML = `
+			.monaco-editor .dirty-diff-modified,
+			.monaco-editor .dirty-diff-added {
+				border-left-width: ${width}px;
+			}`;
+		}
+	}
+
 	private enable(): void {
 		if (this.enabled) {
 			this.disable();

src/vs/workbench/parts/scm/electron-browser/scm.contribution.ts

@@ -79,6 +79,12 @@ Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration).regis
 			enum: ['all', 'gutter', 'overview', 'none'],
 			default: 'all',
 			description: localize('diffDecorations', "Controls diff decorations in the editor.")
+		},
+		'scm.diffGutterWidth': {
+			type: 'number',
+			enum: [1, 2, 3, 4, 5],
+			default: 3,
+			description: localize('diffGutterWidth', "Controls the width(px) of diff decorations in gutter (added & modified).")
 		}
 	}
 });
\ No newline at end of file