fix(schema-compiler): Support zero reference measures other than COUNT(*)

Author: mcheshkov

packages/cubejs-schema-compiler/src/adapter/BaseQuery.js

@@ -1746,6 +1746,13 @@ export class BaseQuery {
 
         let cubeNameToAttach;
         switch (cubeNamesForMeasure.length) {
+          case 0:
+            // For zero reference measure there's nothing to derive info about measure from
+            // So it assume that it's a regular measure, and it will be evaluated on top of join tree
+            return [measureName, [{
+              multiplied: false,
+              measure: m.measure,
+            }]];
           case 1:
             [cubeNameToAttach] = cubeNamesForMeasure;
             break;

packages/cubejs-schema-compiler/test/integration/postgres/member-expressions-on-views.test.ts

@@ -330,6 +330,19 @@ describe('Member expressions on views', () => {
         },
       ],
       testMeasures: [
+        {
+          name: 'one_sum',
+          // eslint-disable-next-line no-template-curly-in-string
+          expression: 'SUM(1)',
+          expectedResults: [
+            {
+              single_cube_one_sum: '1',
+            },
+            {
+              single_cube_one_sum: '2',
+            },
+          ],
+        },
         {
           name: 'val_sum',
           // eslint-disable-next-line no-template-curly-in-string
@@ -383,6 +396,19 @@ describe('Member expressions on views', () => {
         },
       ],
       testMeasures: [
+        {
+          name: 'one_sum',
+          // eslint-disable-next-line no-template-curly-in-string
+          expression: 'SUM(1)',
+          expectedResults: [
+            {
+              single_view_one_sum: '1',
+            },
+            {
+              single_view_one_sum: '2',
+            },
+          ],
+        },
         {
           name: 'val_sum',
           // eslint-disable-next-line no-template-curly-in-string
@@ -448,6 +474,19 @@ describe('Member expressions on views', () => {
         },
       ],
       testMeasures: [
+        {
+          name: 'one_sum',
+          // eslint-disable-next-line no-template-curly-in-string
+          expression: 'SUM(1)',
+          expectedResults: [
+            {
+              many_to_one_view_one_sum: '1',
+            },
+            {
+              many_to_one_view_one_sum: '3',
+            },
+          ],
+        },
         {
           name: 'root_val_sum',
           // eslint-disable-next-line no-template-curly-in-string
@@ -545,6 +584,22 @@ describe('Member expressions on views', () => {
         },
       ],
       testMeasures: [
+        {
+          name: 'one_sum',
+          // eslint-disable-next-line no-template-curly-in-string
+          expression: 'SUM(1)',
+          expectedResults: [
+            {
+              one_to_many_view_one_sum: '3',
+            },
+            {
+              one_to_many_view_one_sum: '1',
+            },
+            {
+              one_to_many_view_one_sum: '2',
+            },
+          ],
+        },
         {
           name: 'root_val_sum',
           // eslint-disable-next-line no-template-curly-in-string