Merge from vscode 718331d6f3ebd1b571530ab499edb266ddd493d5

build/lib/eslint/vscode-dts-event-naming.ts

@@ -0,0 +1,91 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as eslint from 'eslint';
+import { TSESTree, AST_NODE_TYPES } from '@typescript-eslint/experimental-utils';
+
+export = new class ApiEventNaming implements eslint.Rule.RuleModule {
+
+	private static _nameRegExp = /on(Did|Will)([A-Z][a-z]+)([A-Z][a-z]+)?/;
+
+	readonly meta: eslint.Rule.RuleMetaData = {
+		docs: {
+			url: 'https://github.com/microsoft/vscode/wiki/Extension-API-guidelines#event-naming'
+		},
+		messages: {
+			naming: 'Event names must follow this patten: `on[Did|Will]<Verb><Subject>`',
+			verb: 'Unknown verb \'{{verb}}\' - is this really a verb? Iff so, then add this verb to the configuration',
+			subject: 'Unknown subject \'{{subject}}\' - This subject has not been used before but it should refer to something in the API',
+			unknown: 'UNKNOWN event declaration, lint-rule needs tweaking'
+		}
+	};
+
+	create(context: eslint.Rule.RuleContext): eslint.Rule.RuleListener {
+
+		const config = <{ allowed: string[], verbs: string[] }>context.options[0];
+		const allowed = new Set(config.allowed);
+		const verbs = new Set(config.verbs);
+
+		return {
+			['TSTypeAnnotation TSTypeReference Identifier[name="Event"]']: (node: any) => {
+
+				const def = (<TSESTree.Identifier>node).parent?.parent?.parent;
+				let ident: TSESTree.Identifier | undefined;
+
+				if (def?.type === AST_NODE_TYPES.Identifier) {
+					ident = def;
+
+				} else if ((def?.type === AST_NODE_TYPES.TSPropertySignature || def?.type === AST_NODE_TYPES.ClassProperty) && def.key.type === AST_NODE_TYPES.Identifier) {
+					ident = def.key;
+				}
+
+				if (!ident) {
+					// event on unknown structure...
+					return context.report({
+						node,
+						message: 'unknown'
+					});
+				}
+
+				if (allowed.has(ident.name)) {
+					// configured exception
+					return;
+				}
+
+				const match = ApiEventNaming._nameRegExp.exec(ident.name);
+				if (!match) {
+					context.report({
+						node: ident,
+						messageId: 'naming'
+					});
+					return;
+				}
+
+				// check that <verb> is spelled out (configured) as verb
+				if (!verbs.has(match[2].toLowerCase())) {
+					context.report({
+						node: ident,
+						messageId: 'verb',
+						data: { verb: match[2] }
+					});
+				}
+
+				// check that a subject (if present) has occurred
+				if (match[3]) {
+					const regex = new RegExp(match[3], 'ig');
+					const parts = context.getSourceCode().getText().split(regex);
+					if (parts.length < 3) {
+						context.report({
+							node: ident,
+							messageId: 'subject',
+							data: { subject: match[3] }
+						});
+					}
+				}
+			}
+		};
+	}
+};
+