feat: add eslint extend fn

eslint/extend.js

@@ -0,0 +1,59 @@
+// @ts-check
+
+const { getTsconfigPath } = require("./utils/tsconfig");
+
+/**
+ * @typedef EslintConfigName
+ * @type {"base" | "browser-node" | "config-authoring" | "jest" | "next" | "node" | "playwright-test" | "react" | "tailwindcss" | "tsup" | "typescript"}
+ */
+
+/**
+ * @param {EslintConfigName[]} configNames
+ * @param {import("eslint").Linter.Config} extraConfig
+ */
+module.exports = (configNames = [], extraConfig = {}) => {
+  /** @type {import("eslint").Linter.Config} */
+  const config = { ...extraConfig };
+
+  /** @type {import("eslint").Linter.Config["extends"]} */
+  const newExtends = [];
+  configNames.forEach((name) => {
+    require.resolve(`@strangelovelabs/style-guide/eslint/${name}`);
+  });
+  if (typeof extraConfig.extends === "string") {
+    newExtends.push(extraConfig.extends);
+  }
+  if (Array.isArray(extraConfig.extends)) {
+    newExtends.push(...extraConfig.extends);
+  }
+  config.extends = configNames.map((name) => {
+    return require.resolve(`@strangelovelabs/style-guide/eslint/${name}`);
+  });
+
+  /** @type {import("eslint").Linter.Config["ignorePatterns"]} */
+  const newIgnorePatterns = [];
+  if (typeof extraConfig.ignorePatterns === "string") {
+    newIgnorePatterns.push(extraConfig.ignorePatterns);
+  }
+  if (Array.isArray(extraConfig.ignorePatterns)) {
+    newIgnorePatterns.push(...extraConfig.ignorePatterns);
+  }
+  config.ignorePatterns = newIgnorePatterns;
+
+  if (configNames.includes("typescript")) {
+    config.parserOptions = {
+      ...config.parserOptions,
+      project: getTsconfigPath(),
+    };
+    config.settings = {
+      ...config.settings,
+      "import/resolver": {
+        ...config.settings?.["import/resolver"],
+        typescript: {
+          ...config.settings?.["import/resolver"]?.typescript,
+          project: getTsconfigPath(),
+        },
+      },
+    };
+  }
+};