feat: make @testing-library/dom dependency optional (#319)

Author: G-Rath

package.json

@@ -58,6 +58,11 @@
     "@testing-library/dom": "^8.0.0 || ^9.0.0",
     "eslint": "^6.8.0 || ^7.0.0 || ^8.0.0"
   },
+  "peerDependenciesMeta": {
+    "@testing-library/dom": {
+      "optional": true
+    }
+  },
   "eslintConfig": {
     "extends": "./node_modules/kcd-scripts/eslint.js",
     "rules": {

src/__tests__/queries.test.js

@@ -0,0 +1,146 @@
+const TestingLibraryDomRef = { throwWhenRequiring: false };
+
+const requireQueries = (throwWhenRequiring) => {
+  jest.resetModules();
+
+  TestingLibraryDomRef.throwWhenRequiring = throwWhenRequiring;
+
+  return require("../queries");
+};
+
+jest.mock("@testing-library/dom", () => {
+  if (TestingLibraryDomRef.throwWhenRequiring) {
+    throw new (class extends Error {
+      constructor(message) {
+        super(message);
+        this.code = "MODULE_NOT_FOUND";
+      }
+    })();
+  }
+
+  return jest.requireActual("@testing-library/dom");
+});
+
+describe("when @testing-library/dom is not available", () => {
+  it("uses the default queries", () => {
+    const { queries } = requireQueries(true);
+
+    expect([...queries].sort()).toStrictEqual([
+      "findAllByAltText",
+      "findAllByDisplayValue",
+      "findAllByLabelText",
+      "findAllByPlaceholderText",
+      "findAllByRole",
+      "findAllByTestId",
+      "findAllByText",
+      "findAllByTitle",
+      "findByAltText",
+      "findByDisplayValue",
+      "findByLabelText",
+      "findByPlaceholderText",
+      "findByRole",
+      "findByTestId",
+      "findByText",
+      "findByTitle",
+      "getAllByAltText",
+      "getAllByDisplayValue",
+      "getAllByLabelText",
+      "getAllByPlaceholderText",
+      "getAllByRole",
+      "getAllByTestId",
+      "getAllByText",
+      "getAllByTitle",
+      "getByAltText",
+      "getByDisplayValue",
+      "getByLabelText",
+      "getByPlaceholderText",
+      "getByRole",
+      "getByTestId",
+      "getByText",
+      "getByTitle",
+      "queryAllByAltText",
+      "queryAllByDisplayValue",
+      "queryAllByLabelText",
+      "queryAllByPlaceholderText",
+      "queryAllByRole",
+      "queryAllByTestId",
+      "queryAllByText",
+      "queryAllByTitle",
+      "queryByAltText",
+      "queryByDisplayValue",
+      "queryByLabelText",
+      "queryByPlaceholderText",
+      "queryByRole",
+      "queryByTestId",
+      "queryByText",
+      "queryByTitle",
+    ]);
+  });
+});
+
+describe("when @testing-library/dom is available", () => {
+  it("returns the queries from the library", () => {
+    const { queries } = requireQueries(false);
+
+    expect([...queries].sort()).toStrictEqual([
+      "findAllByAltText",
+      "findAllByDisplayValue",
+      "findAllByLabelText",
+      "findAllByPlaceholderText",
+      "findAllByRole",
+      "findAllByTestId",
+      "findAllByText",
+      "findAllByTitle",
+      "findByAltText",
+      "findByDisplayValue",
+      "findByLabelText",
+      "findByPlaceholderText",
+      "findByRole",
+      "findByTestId",
+      "findByText",
+      "findByTitle",
+      "getAllByAltText",
+      "getAllByDisplayValue",
+      "getAllByLabelText",
+      "getAllByPlaceholderText",
+      "getAllByRole",
+      "getAllByTestId",
+      "getAllByText",
+      "getAllByTitle",
+      "getByAltText",
+      "getByDisplayValue",
+      "getByLabelText",
+      "getByPlaceholderText",
+      "getByRole",
+      "getByTestId",
+      "getByText",
+      "getByTitle",
+      "queryAllByAltText",
+      "queryAllByDisplayValue",
+      "queryAllByLabelText",
+      "queryAllByPlaceholderText",
+      "queryAllByRole",
+      "queryAllByTestId",
+      "queryAllByText",
+      "queryAllByTitle",
+      "queryByAltText",
+      "queryByDisplayValue",
+      "queryByLabelText",
+      "queryByPlaceholderText",
+      "queryByRole",
+      "queryByTestId",
+      "queryByText",
+      "queryByTitle",
+    ]);
+  });
+
+  it("re-throws unexpected errors", () => {
+    jest.mock("@testing-library/dom", () => {
+      throw new Error("oh noes!");
+    });
+
+    jest.resetModules();
+
+    expect(() => require("../queries")).toThrow(/oh noes!/iu);
+  });
+});

src/queries.js

@@ -1,3 +1,33 @@
-import { queries as allQueries } from "@testing-library/dom";
+let theQueries = [
+  "findAllBy",
+  "findBy",
+  "getAllBy",
+  "getBy",
+  "queryAllBy",
+  "queryBy",
+].flatMap((prefix) =>
+  [
+    "AltText",
+    "DisplayValue",
+    "LabelText",
+    "PlaceholderText",
+    "Role",
+    "TestId",
+    "Text",
+    "Title",
+  ].map((element) => `${prefix}${element}`)
+);
 
-export const queries = Object.keys(allQueries);
+(() => {
+  try {
+    const { queries: allQueries } = require("@testing-library/dom");
+
+    theQueries = Object.keys(allQueries);
+  } catch (error) {
+    if (error.code !== "MODULE_NOT_FOUND") {
+      throw error;
+    }
+  }
+})();
+
+export const queries = theQueries;