Backport PR #8339

---------

**Commit 1:**
Set minimum aggregation 'Size' input value to 1, because ES will return an error if you provide a size of 0.

- Display feedback if a Dashboard or Visualization is loaded that already violates this constraint.
- Add ElasticsearchError class and isTermSizeZeroError helper.

* Original sha: 4fefae1513
* Authored by CJ Cenizal <cj@cenizal.com> on 2016-09-19T19:02:54Z

src/ui/public/agg_types/controls/order_and_size.html

@@ -17,7 +17,7 @@
       required
       class="form-control"
       type="number"
-      min="0"
+      min="1"
-      >
+    >
   </div>
-</div>
+</div>

src/ui/public/elasticsearch_errors/__tests__/elasticsearch_error.js

@@ -0,0 +1,51 @@
+import sinon from 'auto-release-sinon';
+import expect from 'expect.js';
+import ElasticsearchError from '../elasticsearch_error';
+
+describe('ElasticsearchError', () => {
+  function createError(rootCauses = []) {
+    // Elasticsearch errors are characterized by the resp.error.root_cause array.
+    return {
+      resp: {
+        error: {
+          root_cause: rootCauses.map(rootCause => ({
+            reason: rootCause,
+          })),
+        }
+      }
+    };
+  }
+
+  describe('interface', () => {
+    describe('constructor', () => {
+      it('throws an error if instantiated with a non-elasticsearch error', () => {
+        expect(() => new ElasticsearchError({})).to.throwError();
+      });
+    });
+
+    describe('getRootCauses', () => {
+      it(`returns the root_cause array's reason values`, () => {
+        const rootCauses = ['a', 'b'];
+        const error = createError(rootCauses);
+        const esError = new ElasticsearchError(error);
+        expect(esError.getRootCauses()).to.eql(rootCauses);
+      });
+    });
+
+    describe('hasRootCause', () => {
+      it(`returns true if the cause occurs in the root_cause array's reasons, insensitive to case`, () => {
+        const rootCauses = ['a very detailed error', 'a slightly more detailed error'];
+        const error = createError(rootCauses);
+        const esError = new ElasticsearchError(error);
+        expect(esError.hasRootCause('slightly MORE')).to.be(true);
+      });
+
+      it(`returns false if the cause doesn't occur in the root_cause array's reasons`, () => {
+        const rootCauses = ['a very detailed error', 'a slightly more detailed error'];
+        const error = createError(rootCauses);
+        const esError = new ElasticsearchError(error);
+        expect(esError.hasRootCause('nonexistent error')).to.be(false);
+      });
+    });
+  });
+});

src/ui/public/elasticsearch_errors/__tests__/is_term_size_zero_error.js

@@ -0,0 +1,33 @@
+import sinon from 'auto-release-sinon';
+import expect from 'expect.js';
+import isTermSizeZeroError from '../is_term_size_zero_error';
+
+describe('isTermSizeZeroError', () => {
+  const identifyingString = 'size must be positive, got 0';
+
+  it('returns true if it contains the identifying string', () => {
+    const error = {
+      resp: {
+        error: {
+          root_cause: [{
+            reason: `Some crazy Java exception: ${identifyingString}`,
+          }],
+        }
+      }
+    };
+    expect(isTermSizeZeroError(error)).to.be(true);
+  });
+
+  it(`returns false if it doesn't contain the identifying string`, () => {
+    const error = {
+      resp: {
+        error: {
+          root_cause: [{
+            reason: `Some crazy Java exception`,
+          }],
+        }
+      }
+    };
+    expect(isTermSizeZeroError(error)).to.be(false);
+  });
+});

src/ui/public/elasticsearch_errors/elasticsearch_error.js

@@ -0,0 +1,32 @@
+import _ from 'lodash';
+
+export default class ElasticsearchError {
+  constructor(error) {
+    this.error = error;
+
+    this.getRootCauses = this.getRootCauses.bind(this);
+    this.hasRootCause = this.hasRootCause.bind(this);
+
+    if (!this.getRootCauses().length) {
+      throw new Error(
+        'ElasticsearchError must be instantiated with an elasticsearch error, i.e. it must have' +
+        `a resp.error.root_cause property. Instead got ${JSON.stringify(error)}`
+      );
+    }
+  }
+
+  getRootCauses() {
+    const rootCauses = _.get(this.error, 'resp.error.root_cause');
+    return _.pluck(rootCauses, 'reason');
+  }
+
+  hasRootCause(cause) {
+    const normalizedCause = cause.toLowerCase();
+    const rootCauses = this.getRootCauses();
+    const matchingCauses = rootCauses.filter(rootCause => {
+      const normalizedRootCause = rootCause.toLowerCase();
+      return normalizedRootCause.indexOf(normalizedCause) !== -1;
+    });
+    return matchingCauses.length !== 0;
+  }
+}

src/ui/public/elasticsearch_errors/index.js

@@ -0,0 +1,7 @@
+export {
+  default as ElasticsearchError,
+} from './elasticsearch_error';
+
+export {
+  default as isTermSizeZeroError,
+} from './is_term_size_zero_error';

src/ui/public/elasticsearch_errors/is_term_size_zero_error.js

@@ -0,0 +1,6 @@
+import ElasticsearchError from './elasticsearch_error';
+
+export default function isTermSizeZeroError(error) {
+  const esError = new ElasticsearchError(error);
+  return esError.hasRootCause('size must be positive, got 0');
+}

src/ui/public/visualize/visualize.js

@@ -8,6 +8,10 @@ import uiModules from 'ui/modules';
 import visualizeTemplate from 'ui/visualize/visualize.html';
 import 'angular-sanitize';
 
+import {
+  isTermSizeZeroError,
+} from '../elasticsearch_errors';
+
 uiModules
 .get('kibana/directive', ['ngSanitize'])
 .directive('visualize', function (Notifier, SavedVis, indexPatterns, Private, config, $timeout) {
@@ -155,7 +159,17 @@ uiModules
           return searchSource.onResults().then(onResults);
         }).catch(notify.fatal);
 
-        searchSource.onError(notify.error).catch(notify.fatal);
+        searchSource.onError(e => {
+          if (isTermSizeZeroError(e)) {
+            return notify.error(
+              `Your visualization ('${$scope.vis.title}') has an error: it has a term ` +
+              `aggregation with a size of 0. Please set it to a number greater than 0 to resolve ` +
+              `the error.`
+            );
+          }
+
+          notify.error(e);
+        }).catch(notify.fatal);
       }));
 
       $scope.$watch('esResp', prereq(function (resp, prevResp) {