Improve error handling and move it to API layer

src/api/pushshift/index.js

@@ -4,6 +4,14 @@ export const chunkSize = 100;
 const postURL    = 'https://api.pushshift.io/reddit/submission/search/?ids='
 const commentURL = `https://api.pushshift.io/reddit/comment/search/?size=${chunkSize}&sort=asc&fields=author,body,created_utc,id,link_id,parent_id,retrieved_on,retrieved_utc,score,subreddit&q=*&link_id=`
 
+const errorHandler = (msg, origError, from) => {
+  console.error(from + ': ' + origError)
+  const error = new Error(msg)
+  if (origError.name == 'TypeError')  // Usually indicates that Pushshift is down
+    error.helpUrl = '/about#psdown'
+  throw error
+}
+
 const sleep = ms =>
   new Promise(slept => setTimeout(slept, ms))
 
@@ -62,8 +70,7 @@ export const getPost = async threadID => {
   try {
     return (await fetchJson(`${postURL}${threadID}`)).data[0]
   } catch (error) {
-    console.error('pushshift.getPost: ' + error)
-    throw new Error('Could not get removed post')
+    errorHandler('Could not get removed post', error, 'pushshift.getPost')
   }
 }
 
@@ -75,13 +82,11 @@ export const getComments = async (allComments, threadID, maxComments, after) =>
     while (true) {
       await pushshiftTokenBucket.waitForToken()
       try {
-        comments = (await fetchJson(`${commentURL}${threadID}&after=${after}`)).data
+        comments = (await fetchJson(`${commentURL}${threadID}${after ? `&after=${after}` : ''}`)).data
         break
       } catch (error) {
-        if (delay >= 8000) {  // after ~16s of consecutive failures
-          console.error('pushshift.getComments: ' + error)
-          throw new Error('Could not get removed comments')
-        }
+        if (delay >= 8000)  // after ~16s of consecutive failures
+          errorHandler('Could not get removed comments', error, 'pushshift.getComments')  // rethrows
         delay = delay * 2 || 125
         console.log('pushshift.getComments delay: ' + delay)
         pushshiftTokenBucket.setNextAvail(delay)

src/api/reddit/index.js

@@ -3,11 +3,22 @@ import { fetchJson, chunk } from '../../utils'
 const baseURL = 'https://api.reddit.com'
 const requestSettings = {headers: {"Accept-Language": "en"}}
 
-const errorHandler = (error, from) => {
-  console.error(from + ': ' + error)
-  const e = new Error('Could not connect to Reddit')
-  e.origError = error
-  throw e
+const errorHandler = (origError, from) => {
+  console.error(from + ': ' + origError)
+  const error = new Error('Could not connect to Reddit')
+  if (origError.name == 'TypeError') {  // The exception when blocked by Tracking Protection
+    // https://stackoverflow.com/a/9851769
+    const isFirefox = typeof InstallTrigger !== 'undefined'
+    if (isFirefox)
+      error.helpUrl = '/about#firefox'
+    else {
+      const isChrome = !!window.chrome && (!!window.chrome.webstore || !!window.chrome.runtime)
+      const isEdgeChromium = isChrome && (navigator.userAgent.indexOf("Edg") != -1)
+      if (isEdgeChromium)
+        error.helpUrl = '/about#edge'
+    }
+  }
+  throw error
 }
 
 // Return the post itself

src/pages/thread/index.js

@@ -59,6 +59,7 @@ class Thread extends React.Component {
               }
               this.setState({ post: removedPost })
             })
+            .catch(e => this.props.global.setError(e, e.helpUrl))
         }
       })
       .catch(error => {
@@ -70,7 +71,7 @@ class Thread extends React.Component {
             this.setState({ post: { ...removedPost, removed: true } })
           })
           .catch(error => {
-            this.props.global.setError(error)
+            this.props.global.setError(error, error.helpUrl)
             // Create a dummy post so that comments will still be displayed
             this.setState({ post: { subreddit, id: threadID } })
           })
@@ -168,26 +169,9 @@ class Thread extends React.Component {
               reloadingComments: false
             })
           })
-          .catch(e => {
-            if (e.origError.name == 'TypeError') {  // The exception when blocked by Tracking Protection
-              // https://stackoverflow.com/a/9851769
-              const isFirefox = typeof InstallTrigger !== 'undefined'
-              if (isFirefox) {
-                this.props.global.setError(e, '/about#firefox')
-                return
-              } else {
-                const isChrome = !!window.chrome && (!!window.chrome.webstore || !!window.chrome.runtime)
-                const isEdgeChromium = isChrome && (navigator.userAgent.indexOf("Edg") != -1)
-                if (isEdgeChromium) {
-                  this.props.global.setError(e, '/about#edge')
-                  return
-                }
-              }
-            }
-            throw e
-          })
+          .catch(e => this.props.global.setError(e, e.helpUrl))
       })
-      .catch(this.props.global.setError)
+      .catch(e => this.props.global.setError(e, e.helpUrl))
   }
 
   render () {