expose context key info command, add first version of completion item provider for package.json and keybindings.json files, https://github.com/microsoft/vscode/issues/9303

extensions/configuration-editing/src/configurationEditingMain.ts

@@ -22,6 +22,9 @@ export function activate(context: vscode.ExtensionContext): void {
 
 	// task.json variable suggestions
 	context.subscriptions.push(registerVariableCompletions('**/tasks.json'));
+
+	// keybindings.json/package.json context key suggestions
+	context.subscriptions.push(registerContextKeyCompletions());
 }
 
 function registerSettingsCompletions(): vscode.Disposable {
@@ -136,3 +139,40 @@ vscode.languages.registerDocumentSymbolProvider({ pattern: '**/launch.json', lan
 		return result;
 	}
 }, { label: 'Launch Targets' });
+
+function registerContextKeyCompletions(): vscode.Disposable {
+	type ContextKeyInfo = { key: string, type?: string, description?: string };
+	return vscode.languages.registerCompletionItemProvider(
+		[{ language: 'json', pattern: '**/package.json' }, { language: 'jsonc', pattern: '**/keybindings.json' }],
+		{
+			async provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, token: vscode.CancellationToken) {
+
+				const replacing = document.getWordRangeAtPosition(position, /[\w.-\d]/);
+				const inserting = replacing?.with(undefined, position);
+				if (!replacing || !inserting) {
+					return;
+				}
+
+				const location = getLocation(document.getText(), document.offsetAt(position));
+				if (!location.matches(['*', 'when']) && !location.matches(['contributes', 'menus', '*', '*', 'when'])) {
+					return;
+				}
+
+				const data = await vscode.commands.executeCommand<ContextKeyInfo[]>('getContextKeyInfo');
+				if (token.isCancellationRequested || !data) {
+					return;
+				}
+
+				const result = new vscode.CompletionList();
+				for (const item of data) {
+					const completion = new vscode.CompletionItem(item.key, vscode.CompletionItemKind.Constant);
+					completion.detail = item.type;
+					completion.range = { replacing, inserting };
+					completion.documentation = item.description;
+					result.items.push(completion);
+				}
+				return result;
+			}
+		}
+	);
+}

src/vs/platform/contextkey/browser/contextKeyService.ts

@@ -8,6 +8,7 @@ import { Iterable } from 'vs/base/common/iterator';
 import { IDisposable, DisposableStore, MutableDisposable } from 'vs/base/common/lifecycle';
 import { TernarySearchTree } from 'vs/base/common/map';
 import { distinct } from 'vs/base/common/objects';
+import { localize } from 'vs/nls';
 import { CommandsRegistry } from 'vs/platform/commands/common/commands';
 import { ConfigurationTarget, IConfigurationService } from 'vs/platform/configuration/common/configuration';
 import { IContext, IContextKey, IContextKeyChangeEvent, IContextKeyService, IContextKeyServiceTarget, IReadableSet, SET_CONTEXT_COMMAND_ID, ContextKeyExpression, RawContextKey, ContextKeyInfo } from 'vs/platform/contextkey/common/contextkey';
@@ -578,6 +579,17 @@ CommandsRegistry.registerCommand(SET_CONTEXT_COMMAND_ID, function (accessor, con
 	accessor.get(IContextKeyService).createKey(String(contextKey), contextValue);
 });
 
+CommandsRegistry.registerCommand({
+	id: 'getContextKeyInfo',
+	handler() {
+		return [...RawContextKey.all()].sort((a, b) => a.key.localeCompare(b.key));
+	},
+	description: {
+		description: localize('getContextKeyInfo', "A command that returns information about context keys"),
+		args: []
+	}
+});
+
 CommandsRegistry.registerCommand('_generateContextKeyInfo', function () {
 	const result: ContextKeyInfo[] = [];
 	const seen = new Set<string>();

src/vs/platform/contextkey/common/contextkey.ts

@@ -1259,7 +1259,7 @@ export class ContextKeyOrExpr implements IContextKeyExpression {
 
 export interface ContextKeyInfo {
 	readonly key: string;
-	readonly type: string;
+	readonly type?: string;
 	readonly description?: string;
 }
 
@@ -1281,7 +1281,7 @@ export class RawContextKey<T> extends ContextKeyDefinedExpr {
 		if (typeof metaOrHide === 'object') {
 			RawContextKey._info.push({ ...metaOrHide, key });
 		} else if (metaOrHide !== true) {
-			RawContextKey._info.push({ key, description: metaOrHide, type: typeof defaultValue });
+			RawContextKey._info.push({ key, description: metaOrHide, type: defaultValue !== null && defaultValue !== undefined ? typeof defaultValue : undefined });
 		}
 	}