Updated error handling in bulk example (#927)

Author: delvedor

docs/examples/bulk.asciidoc

@@ -8,57 +8,83 @@ This can greatly increase the indexing speed.
 ----
 'use strict'
 
+require('array.prototype.flatmap').shim()
 const { Client } = require('@elastic/elasticsearch')
-const client = new Client({ node: 'http://localhost:9200' })
+const client = new Client({
+  node: 'http://localhost:9200'
+})
 
 async function run () {
-  const { body: bulkResponse } = await client.bulk({
-    // here we are forcing an index refresh,
-    // otherwise we will not get any result
-    // in the consequent search
-    refresh: true,
-    body: [
-      // operation to perform
-      { index: { _index: 'game-of-thrones' } },
-      // the document to index
-      {
-        character: 'Ned Stark',
-        quote: 'Winter is coming.'
-      },
+  await client.indices.create({
+    index: 'tweets',
+    body: {
+      mappings: {
+        properties: {
+          id: { type: 'integer' },
+          text: { type: 'text' },
+          user: { type: 'keyword' },
+          time: { type: 'date' }
+        }
+      }
+    }
+  }, { ignore: [400] })
 
-      { index: { _index: 'game-of-thrones' } },
-      {
-        character: 'Daenerys Targaryen',
-        quote: 'I am the blood of the dragon.'
-      },
+  const dataset = [{
+    id: 1,
+    text: 'If I fall, don\'t bring me back.',
+    user: 'jon',
+    date: new Date()
+  }, {
+    id: 2,
+    text: 'Witer is coming',
+    user: 'ned',
+    date: new Date()
+  }, {
+    id: 3,
+    text: 'A Lannister always pays his debts.',
+    user: 'tyrion',
+    date: new Date()
+  }, {
+    id: 4,
+    text: 'I am the blood of the dragon.',
+    user: 'daenerys',
+    date: new Date()
+  }, {
+    id: 5, // change this value to a string to see the bulk response with errors
+    text: 'A girl is Arya Stark of Winterfell. And I\'m going home.',
+    user: 'arya',
+    date: new Date()
+  }]
 
-      { index: { _index: 'game-of-thrones' } },
-      {
-        character: 'Tyrion Lannister',
-        quote: 'A mind needs books like a sword needs a whetstone.'
-      }
-    ]
-  })
+  const body = dataset.flatMap(doc => [{ index: { _index: 'tweets' } }, doc])
 
-  if (bulkResponse.errors) {
-    console.log(bulkResponse)
-    process.exit(1)
-  }
+  const { body: bulkResponse } = await client.bulk({ refresh: true, body })
 
-  // Let's search!
-  const { body } = await client.search({
-    index: 'game-of-thrones',
-    body: {
-      query: {
-        match: {
-          quote: 'winter'
-        }
+  if (bulkResponse.errors) {
+    const erroredDocuments = []
+    // The items array has the same order of the dataset we just indexed.
+    // The presence of the `error` key indicates that the operation
+    // that we did for the document has failed.
+    bulkResponse.items.forEach((action, i) => {
+      const operation = Object.keys(action)[0]
+      if (action[operation].error) {
+        erroredDocuments.push({
+          // If the status is 429 it means that you can retry the document,
+          // otherwise it's very likely a mapping error, and you should
+          // fix the document before to try it again.
+          status: action[operation].status,
+          error: action[operation].error,
+          operation: body[i * 2],
+          document: body[i * 2 + 1]
+        })
       }
-    }
-  })
+    })
+    console.log(erroredDocuments)
+  }
 
-  console.log(body.hits.hits)
+  const { body: count } = await client.count({ index: 'tweets' })
+  console.log(count)
 }
 
 run().catch(console.log)
-----
+----