v0.0.4

cloudfunctions/postFavorite/index.js

@@ -0,0 +1,32 @@
+const cloud = require('wx-server-sdk')
+
+cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
+const db = cloud.database()
+const _ = db.command
+
+exports.main = async event => {
+  const { OPENID } = cloud.getWXContext()
+  const { postId, favorited } = event
+  if (!postId) throw new Error('postId is required')
+
+  const existed = await db.collection('postFavorites').where({ postId, openid: OPENID }).limit(1).get()
+  let delta = 0
+
+  if (favorited && !existed.data.length) {
+    await db.collection('postFavorites').add({ data: { postId, openid: OPENID, createdAt: Date.now() } })
+    delta = 1
+  }
+
+  if (!favorited && existed.data.length) {
+    await db.collection('postFavorites').doc(existed.data[0]._id).remove()
+    delta = -1
+  }
+
+  if (delta) {
+    await db.collection('posts').doc(postId).update({ data: { 'counts.favorites': _.inc(delta) } })
+  }
+
+  const post = await db.collection('posts').doc(postId).get()
+  return { favorited: Boolean(favorited), favorites: post.data.counts?.favorites || 0 }
+}
+