Improve response error message (#1457)

lib/errors.js

@@ -90,7 +90,15 @@ class ResponseError extends ElasticsearchClientError {
     super('Response Error')
     Error.captureStackTrace(this, ResponseError)
     this.name = 'ResponseError'
-    this.message = (meta.body && meta.body.error && meta.body.error.type) || 'Response Error'
+    if (meta.body && meta.body.error && meta.body.status) {
+      if (Array.isArray(meta.body.error.root_cause)) {
+        this.message = meta.body.error.root_cause.map(entry => `[${entry.type}] Reason: ${entry.reason}`).join('; ')
+      } else {
+        this.message = 'Response Error'
+      }
+    } else {
+      this.message = 'Response Error'
+    }
     this.meta = meta
   }
 
@@ -108,6 +116,10 @@ class ResponseError extends ElasticsearchClientError {
   get headers () {
     return this.meta.headers
   }
+
+  toString () {
+    return JSON.stringify(this.meta.body)
+  }
 }
 
 class RequestAbortedError extends ElasticsearchClientError {

test/unit/errors.test.js

@@ -103,3 +103,75 @@ test('RequestAbortedError', t => {
   t.true(err.hasOwnProperty('meta'))
   t.end()
 })
+
+test('ResponseError with meaningful message / 1', t => {
+  const meta = {
+    body: {
+      error: {
+        root_cause: [
+          {
+            type: 'index_not_found_exception',
+            reason: 'no such index [foo]',
+            'resource.type': 'index_expression',
+            'resource.id': 'foo',
+            index_uuid: '_na_',
+            index: 'foo'
+          }
+        ],
+        type: 'index_not_found_exception',
+        reason: 'no such index [foo]',
+        'resource.type': 'index_expression',
+        'resource.id': 'foo',
+        index_uuid: '_na_',
+        index: 'foo'
+      },
+      status: 404
+    },
+    statusCode: 404,
+    headers: {}
+  }
+  const err = new errors.ResponseError(meta)
+  t.strictEqual(err.message, '[index_not_found_exception] Reason: no such index [foo]')
+  t.strictEqual(err.toString(), JSON.stringify(meta.body))
+  t.end()
+})
+
+test('ResponseError with meaningful message / 2', t => {
+  const meta = {
+    body: {
+      error: {
+        root_cause: [
+          {
+            type: 'index_not_found_exception',
+            reason: 'no such index [foo]',
+            'resource.type': 'index_expression',
+            'resource.id': 'foo',
+            index_uuid: '_na_',
+            index: 'foo'
+          },
+          {
+            type: 'nested_cause',
+            reason: 'this is a nested cause',
+            'resource.type': 'index_expression',
+            'resource.id': 'foo',
+            index_uuid: '_na_',
+            index: 'foo'
+          }
+        ],
+        type: 'index_not_found_exception',
+        reason: 'no such index [foo]',
+        'resource.type': 'index_expression',
+        'resource.id': 'foo',
+        index_uuid: '_na_',
+        index: 'foo'
+      },
+      status: 404
+    },
+    statusCode: 404,
+    headers: {}
+  }
+  const err = new errors.ResponseError(meta)
+  t.strictEqual(err.message, '[index_not_found_exception] Reason: no such index [foo]; [nested_cause] Reason: this is a nested cause')
+  t.strictEqual(err.toString(), JSON.stringify(meta.body))
+  t.end()
+})