WIP: linter host, VFS, and other related experiments

.vscode/launch.json

@@ -6,7 +6,7 @@
 			"request": "launch",
 			"name": "Run Current File Tests",
 			"program": "${workspaceFolder}/node_modules/vitest/vitest.mjs",
-			"args": ["${fileBasenameNoExtension}"],
+			"args": ["${fileDirname}/${fileBasenameNoExtension}"],
 			"sourceMaps": true,
 			"console": "integratedTerminal",
 			"internalConsoleOptions": "neverOpen"

packages/astro-language/package.json

@@ -0,0 +1,39 @@
+{
+	"name": "@flint.fyi/astro-language",
+	"version": "0.0.1",
+	"description": "[Experimental] TypeScript language plugin for Flint.",
+	"repository": {
+		"type": "git",
+		"url": "https://github.com/JoshuaKGoldberg/flint",
+		"directory": "packages/ts"
+	},
+	"license": "MIT",
+	"author": {
+		"name": "JoshuaKGoldberg",
+		"email": "npm@joshuakgoldberg.com"
+	},
+	"type": "module",
+	"exports": {
+		".": "./lib/index.js"
+	},
+	"dependencies": {
+		"@astrojs/compiler": "^2.13.0",
+		"@astrojs/ts-plugin": "^1.10.6",
+		"@flint.fyi/core": "workspace:",
+		"@flint.fyi/ts": "workspace:",
+		"@flint.fyi/ts-patch": "workspace:",
+		"@flint.fyi/volar-language": "workspace:",
+		"ts-api-utils": "^2.1.0",
+		"typescript": ">=5.9.3"
+	},
+	"devDependencies": {
+		"@flint.fyi/rule-tester": "workspace:"
+	},
+	"engines": {
+		"node": ">=24.0.0"
+	},
+	"publishConfig": {
+		"access": "public",
+		"provenance": true
+	}
+}

packages/astro-language/src/language.ts

@@ -0,0 +1,50 @@
+import { getLanguagePlugin } from "@astrojs/ts-plugin/dist/language.js";
+import { parse } from "@astrojs/compiler/sync";
+import { RootNode } from "@astrojs/compiler/types";
+
+import { RuleReporter } from "@flint.fyi/core";
+
+import { setTSExtraSupportedExtensions } from "@flint.fyi/ts-patch";
+import { createVolarBasedLanguage } from "@flint.fyi/volar-language";
+
+setTSExtraSupportedExtensions([".astro"]);
+
+export interface AstroServices {
+	astroServices?: {
+		ast: RootNode;
+		reportComponent: RuleReporter<string>;
+	};
+}
+
+export const astroLanguage = createVolarBasedLanguage<AstroServices>(
+	(ts, options) => {
+		return {
+			languagePlugins: getLanguagePlugin(),
+			prepareFile(
+				filePathAbsolute,
+				{ program, sourceFile },
+				volarLanguage,
+				sourceScript,
+			) {
+				const sourceText = sourceScript.snapshot.getText(
+					0,
+					sourceScript.snapshot.getLength(),
+				);
+				// TODO: report parsing errors?
+				const { ast } = parse(sourceText, { position: true });
+				return {
+					// TODO: first statement
+					firstStatementPosition: sourceText.length,
+					extraContext(reportTranslated) {
+						return {
+							astroServices: {
+								ast,
+								reportComponent: reportTranslated,
+							},
+						};
+					},
+				};
+			},
+		};
+	},
+);

packages/astro-language/src/rules/anyReturns.test.ts

@@ -0,0 +1,53 @@
+import rule from "../../../ts/lib/rules/anyReturns.js";
+import { astroLanguage } from "../language.js";
+import { ruleTester } from "./ruleTester.js";
+
+ruleTester.describe(astroLanguage.createRule(rule), {
+	invalid: [
+		{
+			code: `
+---
+function foo() {
+	return 1 as any
+}
+---
+			`,
+			snapshot: `
+---
+function foo() {
+	return 1 as any
+	~~~~~~~~~~~~~~~
+	Unsafe return of a value of type \`any\`.
+}
+---
+			`,
+		},
+		{
+			code: `
+{
+function foo() {
+	return 1 as any
+}
+}
+			`,
+			snapshot: `
+{
+function foo() {
+	return 1 as any
+	~~~~~~~~~~~~~~~
+	Unsafe return of a value of type \`any\`.
+}
+}
+			`,
+		},
+	],
+	valid: [
+		`
+---
+function foo() {
+	return 1
+}
+---
+		`,
+	],
+});

packages/astro-language/src/rules/ruleTester.ts

@@ -0,0 +1,11 @@
+import { createRuleTesterTSHost, RuleTester } from "@flint.fyi/rule-tester";
+import { describe, it } from "vitest";
+
+export const ruleTester = new RuleTester({
+	describe,
+	it,
+	defaults: {
+		fileName: "file.astro",
+	},
+	host: createRuleTesterTSHost(import.meta.dirname),
+});

packages/astro-language/src/rules/setHtmlDirectives.test.ts

@@ -0,0 +1,57 @@
+import rule from "./setHtmlDirectives.js";
+import { ruleTester } from "./ruleTester.js";
+
+ruleTester.describe(rule, {
+	invalid: [
+		{
+			code: `
+---
+let string = 'this string contains some <strong>HTML!!!</strong>'
+---
+
+<p set:html={string}></p>
+			`,
+			snapshot: `
+---
+let string = 'this string contains some <strong>HTML!!!</strong>'
+---
+
+<p set:html={string}></p>
+   ~~~~~~~~
+   TODO: don't use set:html to reduce XSS risk
+			`,
+		},
+		{
+			code: `
+<div>
+	<p set:html=\`this string contains some <strong>HTML!!!</strong>\`></p>
+</div>
+			`,
+			snapshot: `
+<div>
+	<p set:html=\`this string contains some <strong>HTML!!!</strong>\`></p>
+	   ~~~~~~~~
+	   TODO: don't use set:html to reduce XSS risk
+</div>
+			`,
+		},
+	],
+	valid: [
+		`
+---
+let string = 'this string contains some <strong>HTML!!!</strong>'
+---
+
+<p set:text={string}></p>
+		`,
+		"<p set:text=`this string contains some <strong>HTML!!!</strong>`></p>",
+		`
+---
+let string = 'this string contains some <strong>HTML!!!</strong>'
+---
+
+<p>{string}</p>
+		`,
+		"<p>{`this string contains some <strong>HTML!!!</strong>`}</p>",
+	],
+});

packages/astro-language/src/rules/setHtmlDirectives.ts

@@ -0,0 +1,42 @@
+import { astroLanguage } from "../language.js";
+
+export default astroLanguage.createRule({
+	about: {
+		description: "TODO",
+		id: "setHtmlDirectives",
+		preset: "logical",
+	},
+	messages: {
+		setHtml: {
+			primary: `TODO: don't use set:html to reduce XSS risk`,
+			secondary: ["TODO"],
+			suggestions: ["TODO"],
+		},
+	},
+	setup(context) {
+		const { astroServices } = context;
+		if (astroServices == null) {
+			return undefined;
+		}
+		astroServices.ast.children.forEach(function visit(node) {
+			if ("attributes" in node) {
+				for (const attr of node.attributes) {
+					if (attr.name === "set:html") {
+						const begin = attr.position!.start.offset;
+						astroServices.reportComponent({
+							message: "setHtml",
+							range: {
+								begin,
+								end: begin + attr.name.length,
+							},
+						});
+					}
+				}
+			}
+			if ("children" in node) {
+				node.children.forEach(visit);
+			}
+		});
+		return undefined;
+	},
+});

packages/astro-language/tsconfig.json

@@ -0,0 +1,15 @@
+{
+	"compilerOptions": {
+		"outDir": "lib",
+		"rootDir": "src"
+	},
+	"extends": "../../tsconfig.base.json",
+	"include": ["src"],
+	"references": [
+		{ "path": "../core" },
+		{ "path": "../ts" },
+		{ "path": "../rule-tester" },
+		{ "path": "../ts-patch" },
+		{ "path": "../volar-language" }
+	]
+}

packages/core/src/host/createFSBackedLinterHost.ts

@@ -0,0 +1,65 @@
+import fs from "node:fs";
+import path from "node:path";
+import { LinterHost, LinterHostDirectoryEntry } from "../types/host.js";
+import { normalizePath } from "./normalizePath.js";
+
+export function createFSBackedLinterHost(cwd: string): LinterHost {
+	cwd = normalizePath(cwd);
+
+	return {
+		getCurrentDirectory() {
+			return cwd;
+		},
+		stat(pathAbsolute) {
+			try {
+				const stat = fs.statSync(pathAbsolute);
+				if (stat.isDirectory()) {
+					return "directory";
+				}
+				if (stat.isFile()) {
+					return "file";
+				}
+			} catch {}
+			return undefined;
+		},
+		readDirectory(directoryPathAbsolute) {
+			const result: LinterHostDirectoryEntry[] = [];
+			const dirents = fs.readdirSync(directoryPathAbsolute, {
+				withFileTypes: true,
+			});
+
+			for (let entry of dirents) {
+				let stat = entry as Pick<typeof entry, "isFile" | "isDirectory">;
+				if (entry.isSymbolicLink()) {
+					try {
+						stat = fs.statSync(path.join(directoryPathAbsolute, entry.name));
+					} catch {
+						continue;
+					}
+				}
+				if (stat.isDirectory()) {
+					result.push({ type: "directory", name: entry.name });
+				}
+				if (stat.isFile()) {
+					result.push({ type: "file", name: entry.name });
+				}
+			}
+
+			return result;
+		},
+		readFile(filePathAbsolute) {
+			return fs.readFileSync(filePathAbsolute, "utf8");
+		},
+		// TODO
+		watchFile(filePathAbsolute, callback) {
+			return {
+				[Symbol.dispose]() {},
+			};
+		},
+		watchDirectory(directoryPathAbsolute, recursive, callback) {
+			return {
+				[Symbol.dispose]() {},
+			};
+		},
+	};
+}