Add unit tests for terms expression function.

src/plugins/data/public/search/aggs/buckets/terms_fn.test.ts

@@ -0,0 +1,144 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { functionWrapper } from '../test_helpers';
+import { aggTypeTerms } from './terms_fn';
+
+describe('agg_expression_functions', () => {
+  describe('aggTypeTerms', () => {
+    const fn = functionWrapper(aggTypeTerms());
+
+    it('fills in defaults when only required args are provided', () => {
+      const actual = fn({
+        field: 'machine.os.keyword',
+        order: 'asc',
+        orderBy: '1',
+      });
+      expect(actual).toMatchInlineSnapshot(`
+        Object {
+          "type": "agg_type",
+          "value": Object {
+            "enabled": true,
+            "id": undefined,
+            "params": Object {
+              "exclude": undefined,
+              "field": "machine.os.keyword",
+              "include": undefined,
+              "missingBucket": false,
+              "missingBucketLabel": "Missing",
+              "order": "asc",
+              "orderAgg": undefined,
+              "orderBy": "1",
+              "otherBucket": false,
+              "otherBucketLabel": "Other",
+              "size": 5,
+            },
+            "schema": undefined,
+            "type": "terms",
+          },
+        }
+      `);
+    });
+
+    it('includes optional params when they are provided', () => {
+      const actual = fn({
+        id: '1',
+        enabled: false,
+        schema: 'whatever',
+        field: 'machine.os.keyword',
+        order: 'desc',
+        orderBy: '2',
+        size: 6,
+        missingBucket: true,
+        missingBucketLabel: 'missing',
+        otherBucket: true,
+        otherBucketLabel: 'other',
+        exclude: 'ios',
+      });
+
+      expect(actual.value).toMatchInlineSnapshot(`
+        Object {
+          "enabled": false,
+          "id": "1",
+          "params": Object {
+            "exclude": "ios",
+            "field": "machine.os.keyword",
+            "include": undefined,
+            "missingBucket": true,
+            "missingBucketLabel": "missing",
+            "order": "desc",
+            "orderAgg": undefined,
+            "orderBy": "2",
+            "otherBucket": true,
+            "otherBucketLabel": "other",
+            "size": 6,
+          },
+          "schema": "whatever",
+          "type": "terms",
+        }
+      `);
+    });
+
+    it('handles orderAgg as a subexpression', () => {
+      const actual = fn({
+        field: 'machine.os.keyword',
+        order: 'asc',
+        orderBy: '1',
+        orderAgg: fn({ field: 'name', order: 'asc', orderBy: '1' }),
+      });
+
+      expect(actual.value.params).toMatchInlineSnapshot(`
+        Object {
+          "exclude": undefined,
+          "field": "machine.os.keyword",
+          "include": undefined,
+          "missingBucket": false,
+          "missingBucketLabel": "Missing",
+          "order": "asc",
+          "orderAgg": Object {
+            "type": "agg_type",
+            "value": Object {
+              "enabled": true,
+              "id": undefined,
+              "params": Object {
+                "exclude": undefined,
+                "field": "name",
+                "include": undefined,
+                "missingBucket": false,
+                "missingBucketLabel": "Missing",
+                "order": "asc",
+                "orderAgg": undefined,
+                "orderBy": "1",
+                "otherBucket": false,
+                "otherBucketLabel": "Other",
+                "size": 5,
+              },
+              "schema": undefined,
+              "type": "terms",
+            },
+          },
+          "orderBy": "1",
+          "otherBucket": false,
+          "otherBucketLabel": "Other",
+          "size": 5,
+        }
+      `);
+    });
+  });
+});

src/plugins/data/public/search/aggs/test_helpers/function_wrapper.ts

@@ -0,0 +1,49 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { mapValues } from 'lodash';
+import {
+  AnyExpressionFunctionDefinition,
+  ExpressionFunctionDefinition,
+  ExecutionContext,
+} from '../../../../../../plugins/expressions/public';
+
+/**
+ * Takes a function spec and passes in default args,
+ * overriding with any provided args.
+ *
+ * Similar to the test helper used in Expressions & Canvas,
+ * however in this case we are ignoring the input & execution
+ * context, as they are not applicable to the agg type
+ * expression functions.
+ */
+export const functionWrapper = <T extends AnyExpressionFunctionDefinition>(spec: T) => {
+  const defaultArgs = mapValues(spec.args, argSpec => argSpec.default);
+  return (
+    args: T extends ExpressionFunctionDefinition<
+      infer Name,
+      infer Input,
+      infer Arguments,
+      infer Output,
+      infer Context
+    >
+      ? Arguments
+      : never
+  ) => spec.fn(null, { ...defaultArgs, ...args }, {} as ExecutionContext);
+};

src/plugins/data/public/search/aggs/test_helpers/index.ts

@@ -17,5 +17,6 @@
  * under the License.
  */
 
+export { functionWrapper } from './function_wrapper';
 export { mockAggTypesRegistry } from './mock_agg_types_registry';
 export { mockDataServices } from './mock_data_services';