Allow type imports only in webview preloads (#204639)

.eslintplugin/code-no-runtime-import.ts

@@ -0,0 +1,66 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { TSESTree } from '@typescript-eslint/typescript-estree';
+import * as eslint from 'eslint';
+import { dirname, join, relative } from 'path';
+import minimatch from 'minimatch';
+import { createImportRuleListener } from './utils';
+
+export = new class implements eslint.Rule.RuleModule {
+
+	readonly meta: eslint.Rule.RuleMetaData = {
+		messages: {
+			layerbreaker: 'You are only allowed to import {{import}} from here using `import type ...`.'
+		},
+		schema: {
+			type: "array",
+			items: {
+				type: "object",
+				additionalProperties: {
+					type: "array",
+					items: {
+						type: "string"
+					}
+				}
+			}
+		}
+	};
+
+	create(context: eslint.Rule.RuleContext): eslint.Rule.RuleListener {
+		let fileRelativePath = relative(dirname(__dirname), context.getFilename());
+		if (!fileRelativePath.endsWith('/')) {
+			fileRelativePath += '/';
+		}
+		const ruleArgs = <Record<string, string[]>>context.options[0];
+
+		const matchingKey = Object.keys(ruleArgs).find(key => fileRelativePath.startsWith(key) || minimatch(fileRelativePath, key));
+		if (!matchingKey) {
+			// nothing
+			return {};
+		}
+
+		const restrictedImports = ruleArgs[matchingKey];
+		return createImportRuleListener((node, path) => {
+			if (path[0] === '.') {
+				path = join(dirname(context.getFilename()), path);
+			}
+
+			if ((
+				restrictedImports.includes(path) || restrictedImports.some(restriction => minimatch(path, restriction))
+			) && !(
+				(node.parent?.type === TSESTree.AST_NODE_TYPES.ImportDeclaration && node.parent.importKind === 'type') ||
+				(node.parent && 'exportKind' in node.parent && node.parent.exportKind === 'type'))) { // the export could be multiple types
+				context.report({
+					loc: node.parent!.loc,
+					messageId: 'layerbreaker',
+					data: {
+						import: path
+					}
+				});
+			}
+		});
+	}
+};

.eslintrc.json

@@ -1087,6 +1087,19 @@
 					}
 				]
 			}
+		},
+		{
+			"files": [
+				"src/vs/workbench/contrib/notebook/browser/view/renderers/*.ts"
+			],
+			"rules": {
+				"local/code-no-runtime-import": [
+					"error",
+					{
+						"src/vs/workbench/contrib/notebook/browser/view/renderers/webviewPreloads.ts": ["**/*"]
+					}
+				]
+			}
 		}
 	]
 }