Merge branch 'master' into add-ontransformend

Author: eduardoboucas

lib/file-writers.js

@@ -6,13 +6,13 @@ const writeFile = util.promisify(fs.writeFile);
 
 module.exports.writeFrontmatterMarkdown = (
   filePath,
-  { body = "", frontmatter }
+  { body = "", frontmatter = {} }
 ) => {
   const lines = [
     "---",
     yaml.stringify(frontmatter).trim(),
     "---",
-    body.length > 0 ? body.trim() : "",
+    body ? body.toString().trim() : "",
     ""
   ];
   const content = lines.join("\n");

lib/file-writers.test.js

@@ -0,0 +1,55 @@
+const util = require("util");
+
+const mockPromisifiedFunction = jest.fn();
+
+util.promisify = jest.fn(() => mockPromisifiedFunction);
+
+jest.mock("fs");
+
+const fileWriters = require("./file-writers");
+
+afterEach(() => {
+  jest.clearAllMocks();
+});
+
+describe("`writeFrontmatterMarkdown()`", () => {
+  test("writes Markdown files with frontmatter", () => {
+    const mockContent = {
+      body: "This is the body",
+      frontmatter: {
+        name: "John Doe"
+      }
+    };
+    const mockPath = "/Users/johndoe/file.md";
+
+    fileWriters.writeFrontmatterMarkdown(mockPath, mockContent);
+
+    expect(mockPromisifiedFunction).toHaveBeenCalledTimes(1);
+
+    const [filePath, content] = mockPromisifiedFunction.mock.calls[0];
+
+    expect(filePath).toBe(mockPath);
+    expect(content).toBe(
+      `---\nname: ${mockContent.frontmatter.name}\n---\n${mockContent.body}\n`
+    );
+  });
+
+  test("converts body to string", () => {
+    const mockContent = {
+      body: [1, 2, 3],
+      frontmatter: {
+        name: "John Doe"
+      }
+    };
+    const mockPath = "/Users/johndoe/file.md";
+
+    fileWriters.writeFrontmatterMarkdown(mockPath, mockContent);
+
+    expect(mockPromisifiedFunction).toHaveBeenCalledTimes(1);
+
+    const [filePath, content] = mockPromisifiedFunction.mock.calls[0];
+
+    expect(filePath).toBe(mockPath);
+    expect(content).toBe("---\nname: John Doe\n---\n1,2,3\n");
+  });
+});