Allow showTextDocument to open notebook cell URIs (microsoft#158477)

* Fix microsoft#123270

* Update to use `getCodeEditor`

Author: lramos15

extensions/vscode-api-tests/src/singlefolder-tests/notebook.api.test.ts

@@ -188,7 +188,7 @@ const apiTestContentProvider: vscode.NotebookContentProvider = {
 		assert.strictEqual(firstNotebookEditor?.notebook, secondNotebookEditor?.notebook, 'split notebook editors share the same document');
 	});
 
-	test.skip('#106657. Opening a notebook from markers view is broken ', async function () {
+	test('#106657. Opening a notebook from markers view is broken ', async function () {
 
 		const document = await openRandomNotebookDocument();
 		const [cell] = document.getCells();

src/vs/editor/browser/editorBrowser.ts

@@ -1227,6 +1227,10 @@ export function getCodeEditor(thing: unknown): ICodeEditor | null {
 		return thing.getModifiedEditor();
 	}
 
+	if (isCompositeEditor(thing) && isCodeEditor(thing.activeCodeEditor)) {
+		return thing.activeCodeEditor;
+	}
+
 	return null;
 }
 

src/vs/workbench/api/browser/mainThreadEditors.ts

@@ -13,7 +13,7 @@ import { ISelection } from 'vs/editor/common/core/selection';
 import { IDecorationOptions, IDecorationRenderOptions } from 'vs/editor/common/editorCommon';
 import { ISingleEditOperation } from 'vs/editor/common/core/editOperation';
 import { CommandsRegistry } from 'vs/platform/commands/common/commands';
-import { ITextEditorOptions, IResourceEditorInput, EditorActivation } from 'vs/platform/editor/common/editor';
+import { ITextEditorOptions, IResourceEditorInput, EditorActivation, EditorResolution } from 'vs/platform/editor/common/editor';
 import { ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
 import { MainThreadTextEditor } from 'vs/workbench/api/browser/mainThreadEditor';
 import { ExtHostContext, ExtHostEditorsShape, IApplyEditsOptions, ITextDocumentShowOptions, ITextEditorConfigurationUpdate, ITextEditorPositionData, IUndoStopOptions, MainThreadTextEditorsShape, TextEditorRevealType } from 'vs/workbench/api/common/extHost.protocol';
@@ -25,8 +25,8 @@ import { IWorkingCopyService } from 'vs/workbench/services/workingCopy/common/wo
 import { ExtensionIdentifier } from 'vs/platform/extensions/common/extensions';
 import { ILineChange } from 'vs/editor/common/diff/smartLinesDiffComputer';
 import { IExtHostContext } from 'vs/workbench/services/extensions/common/extHostCustomers';
-import { DEFAULT_EDITOR_ASSOCIATION, IEditorControl } from 'vs/workbench/common/editor';
-import { ICodeEditor } from 'vs/editor/browser/editorBrowser';
+import { IEditorControl } from 'vs/workbench/common/editor';
+import { getCodeEditor, ICodeEditor } from 'vs/editor/browser/editorBrowser';
 import { IConfigurationService } from 'vs/platform/configuration/common/configuration';
 
 export interface IMainThreadEditorLocator {
@@ -127,7 +127,7 @@ export class MainThreadTextEditors implements MainThreadTextEditorsShape {
 			// preserve pre 1.38 behaviour to not make group active when preserveFocus: true
 			// but make sure to restore the editor to fix https://github.com/microsoft/vscode/issues/79633
 			activation: options.preserveFocus ? EditorActivation.RESTORE : undefined,
-			override: DEFAULT_EDITOR_ASSOCIATION.id
+			override: EditorResolution.EXCLUSIVE_ONLY
 		};
 
 		const input: IResourceEditorInput = {
@@ -139,7 +139,10 @@ export class MainThreadTextEditors implements MainThreadTextEditorsShape {
 		if (!editor) {
 			return undefined;
 		}
-		return this._editorLocator.findTextEditorIdFor(editor);
+		// Composite editors are made up of many editors so we return the active one at the time of opening
+		const editorControl = editor.getControl();
+		const codeEditor = getCodeEditor(editorControl);
+		return codeEditor ? this._editorLocator.getIdOfCodeEditor(codeEditor) : undefined;
 	}
 
 	async $tryShowEditor(id: string, position?: EditorGroupColumn): Promise<void> {