Add test for overridding existing markdown file

src/generate.js

@@ -9,14 +9,14 @@ const defaultDir = './posts';
 export const savePost = (dir = defaultDir) => postData => {
   if (!postData) return false;
 
-  const { content, fileName } = postData;
-  const filePath = `${dir}/${fileName}`;
+  const { markdown, props } = postData;
+  const filePath = `${dir}/${props.fileName}`;
 
   return new Promise((resolve, reject) => {
     mkdir(dir, err => {
       if (err && reject) return reject(err);
-      fs.writeFileSync(filePath, content);
-      resolve(filePath);
+      fs.writeFileSync(filePath, markdown);
+      resolve(props);
     });
   });
 };
@@ -28,10 +28,10 @@ export const generate = (dir = defaultDir) => (posts = []) => {
     const props = mapDataToProps(post);
     if (!isValidPost(props)) return;
 
-    const content = generatePost(props);
+    const markdown = generatePost(props);
     const postData = {
-      fileName: props.fileName,
-      content,
+      props,
+      markdown,
     };
 
     saveQueue.push(savePost(dir)(postData));

src/tests/generate.spec.js

@@ -26,4 +26,37 @@ describe('generate', () => {
         done(err);
       });
   });
+
+  it('should overwrite existing .md post', done => {
+    generate(dir)(posts)
+      .then(() => {
+        // Regenerate, but with new post
+        const newTitle = 'NEWTITLE. OMG!!!';
+        const newPost = Object.assign({}, data, {
+          html_title: newTitle,
+        });
+
+        generate(dir)([newPost])
+          .then(postData => {
+            const postProps = mapDataToProps(newPost);
+            const post = readPost(dir)(postProps);
+
+            expect(post).to.exist;
+            expect(post).to.be.a('string');
+
+            expect(post).to.contain(postProps.front_matter.title);
+            expect(post).to.contain(postProps.front_matter.description);
+            expect(post).to.contain(postProps.content);
+            expect(post).to.contain(newTitle);
+
+            done();
+          })
+          .catch(err => {
+            done(err);
+          });
+      })
+      .catch(err => {
+        done(err);
+      });
+  });
 });