fix alter table issue

Author: oguimbal

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pg-mem",
-  "version": "1.0.20",
+  "version": "1.0.21",
   "description": "A memory version of postgres",
   "main": "index.js",
   "scripts": {

src/table.ts

@@ -20,7 +20,7 @@ type Raw<T> = ImMap<string, T>;
 export class MemoryTable<T = any> extends DataSourceBase<T> implements IMemoryTable, _ITable<T> {
 
     private handlers = new Map<TableEvent, Set<() => void>>();
-    readonly selection: _ISelection<T>;
+    readonly selection: Alias<T>;
     private it = 0;
     hasPrimary: boolean;
     private readonly: boolean;
@@ -54,7 +54,7 @@ export class MemoryTable<T = any> extends DataSourceBase<T> implements IMemoryTa
     constructor(readonly schema: _ISchema, t: _Transaction, _schema: Schema) {
         super(schema);
         this.name = _schema.name;
-        this.selection = buildAlias(this, this.name);
+        this.selection = buildAlias(this, this.name) as Alias<T>;
 
         // fields
         for (const s of _schema.fields) {
@@ -157,6 +157,7 @@ export class MemoryTable<T = any> extends DataSourceBase<T> implements IMemoryTa
         // once constraints created, reference them. (constraint creation might have thrown)m
         this.columns.push(cref.expression);
         this.schema.db.onSchemaChange();
+        this.selection.rebuild();
     }
 
 

src/tests/insert.queries.spec.ts

@@ -132,4 +132,11 @@ describe('[Queries] Inserts', () => {
             .to.deep.equal([{ id: 1 }]);
     })
 
+    it('[bugfix] allows returning statement', () => {
+        expect(many(`CREATE TABLE "user" ("id" SERIAL NOT NULL, "name" text NOT NULL, CONSTRAINT "PK_cace4a159ff9f2512dd42373760" PRIMARY KEY ("id"));
+                ALTER TABLE "user" ADD data jsonb;
+                INSERT INTO "user"("name", "data") VALUES ('me', '{"tags":["nice"]}') RETURNING "id";`))
+            .to.deep.equal([{ id: 1 }])
+    })
+
 });

src/transforms/alias.ts

@@ -14,6 +14,12 @@ export function buildAlias(on: _ISelection, alias?: string): _ISelection<any> {
 
 export class Alias<T> extends TransformBase<T>{
 
+    rebuild() {
+        this._columns = null;
+        this.oldToThis.clear();
+        this.thisToOld.clear();
+    }
+
     private oldToThis = new Map<IValue, IValue>();
     private thisToOld = new Map<IValue, IValue>();
     get debugId() {