introduce alias in CubeValidator

and cover it with schema tests

Author: KSDaemon

packages/cubejs-schema-compiler/src/compiler/CubeValidator.ts

@@ -818,7 +818,8 @@ const baseSchema = {
         'belongsTo', 'belongs_to', 'many_to_one', 'manyToOne',
         'hasMany', 'has_many', 'one_to_many', 'oneToMany',
         'hasOne', 'has_one', 'one_to_one', 'oneToOne'
-      ).required()
+      ).required(),
+      alias: identifier,
     }))
   ]),
   measures: MeasuresSchema,

packages/cubejs-schema-compiler/test/unit/__snapshots__/schema.test.ts.snap

@@ -1729,6 +1729,33 @@ Array [
 ]
 `;
 
+exports[`Schema Testing Joins join aliases (joins as array) 1`] = `
+Array [
+  Object {
+    "alias": "CubeB_alias1",
+    "name": "CubeB",
+    "relationship": "hasOne",
+    "sql": [Function],
+  },
+  Object {
+    "alias": "CubeB_alias2",
+    "name": "CubeB",
+    "relationship": "hasOne",
+    "sql": [Function],
+  },
+  Object {
+    "name": "CubeC",
+    "relationship": "hasMany",
+    "sql": [Function],
+  },
+  Object {
+    "name": "CubeD",
+    "relationship": "belongsTo",
+    "sql": [Function],
+  },
+]
+`;
+
 exports[`Schema Testing Views allows to override \`title\`, \`description\`, \`meta\`, and \`format\` on includes members 1`] = `
 Object {
   "accessPolicy": undefined,

packages/cubejs-schema-compiler/test/unit/schema.test.ts

@@ -487,6 +487,50 @@ describe('Schema Testing', () => {
 
       expect(cubeEvaluator.cubeFromPath('CubeA').joins).toMatchSnapshot();
     });
+
+    it('join aliases (joins as array)', async () => {
+      const { compiler, cubeEvaluator } = prepareJsCompiler([
+        createCubeSchema({
+          name: 'CubeA',
+          joins: `[
+            {
+              name: 'CubeB',
+              sql: \`SQL ON clause1\`,
+              relationship: 'one_to_one',
+              alias: 'CubeB_alias1'
+            },
+            {
+              name: 'CubeB',
+              sql: \`SQL ON clause2\`,
+              relationship: 'one_to_one',
+              alias: 'CubeB_alias2'
+            },
+            {
+              name: 'CubeC',
+              sql: \`SQL ON clause\`,
+              relationship: 'one_to_many'
+            },
+            {
+              name: 'CubeD',
+              sql: \`SQL ON clause\`,
+              relationship: 'many_to_one'
+            },
+          ]`
+        }),
+        createCubeSchema({
+          name: 'CubeB',
+        }),
+        createCubeSchema({
+          name: 'CubeC',
+        }),
+        createCubeSchema({
+          name: 'CubeD',
+        }),
+      ]);
+      await compiler.compile();
+
+      expect(cubeEvaluator.cubeFromPath('CubeA').joins).toMatchSnapshot();
+    });
   });
 
   describe('Access Policies', () => {

packages/cubejs-schema-compiler/test/unit/yaml-schema.test.ts

@@ -629,4 +629,51 @@ describe('Yaml Schema Testing', () => {
 
     await compiler.compile();
   });
+
+  it('joins with aliases - success', async () => {
+    const { compiler } = prepareYamlCompiler(
+      `
+      cubes:
+      - name: CubeA
+        sql: "select * from tbl"
+        joins:
+          - name: CubeB
+            sql: SQL ON clause1
+            relationship: one_to_one
+            alias: CubeB_alias1
+
+          - name: CubeB
+            sql: SQL ON clause2
+            relationship: one_to_one
+            alias: CubeB_alias2
+
+          - name: CubeC
+            sql: SQL ON clause
+            relationship: one_to_many
+
+          - name: CubeD
+            sql: SQL ON clause
+            relationship: many_to_one
+        dimensions:
+          - name: id
+            sql: id
+            type: number
+            primary_key: true
+          - name: created_at
+            sql: created_at
+            type: time
+        measures:
+          - name: count
+            type: count
+      - name: CubeB
+        sql: "select * from tbl"
+      - name: CubeC
+        sql: "select * from tbl"
+      - name: CubeD
+        sql: "select * from tbl"
+      `
+    );
+
+    await compiler.compile();
+  });
 });