Condition this behavior on ##! unsafe_complex_select_query compiler flag

Author: christopherswenson

packages/malloy/src/model/malloy_query.ts

@@ -131,6 +131,7 @@ import {
   shouldMaterialize,
 } from './materialization/utils';
 import {EventStream} from '../runtime_types';
+import {Tag} from '../tags';
 
 interface TurtleDefPlus extends TurtleDef, Filtered {}
 
@@ -3411,6 +3412,13 @@ class QueryQuery extends QueryField {
     };
     this.generateStage0Fields(this.rootResult, f, stageWriter);
 
+    if (
+      this.firstSegment.type === 'project' &&
+      !this.parent.modelCompilerFlags().has('unsafe_complex_select_query')
+    ) {
+      throw new Error('PROJECT cannot be used on queries with turtles');
+    }
+
     const groupBy = 'GROUP BY ' + f.dimensionIndexes.join(',') + '\n';
 
     from += this.parent.dialect.sqlGroupSetTable(this.maxGroupSet) + '\n';
@@ -4309,6 +4317,16 @@ class QueryStruct {
     this.addFieldsFromFieldList(structDef.fields);
   }
 
+  private _modelTag: Tag | undefined = undefined;
+  modelCompilerFlags(): Tag {
+    if (this._modelTag === undefined) {
+      const annotation = this.structDef.modelAnnotation;
+      const {tag} = Tag.annotationToTag(annotation, {prefix: /^##!\s*/});
+      this._modelTag = tag;
+    }
+    return this._modelTag;
+  }
+
   protected findFirstDialect(): string {
     if (isSourceDef(this.structDef)) {
       return this.structDef.dialect;

test/src/databases/all/functions.spec.ts

@@ -1745,14 +1745,15 @@ describe.each(runtimes.runtimeList)('%s', (databaseName, runtime) => {
     it('can be used in a select', async () => {
       await expect(`
         ##! experimental { function_order_by partition_by }
+        ##! unsafe_complex_select_query
         run: state_facts -> {
           select: state, births, popular_name
           calculate: prev_births_by_name is lag(births) {
             partition_by: popular_name
             order_by: births desc
           }
           order_by: births desc
-          limit: 10
+          limit: 3
         }
       `).malloyResultMatches(expressionModel, [
         {
@@ -1773,48 +1774,6 @@ describe.each(runtimes.runtimeList)('%s', (databaseName, runtime) => {
           popular_name: 'Isabella',
           prev_births_by_name: 23694136,
         },
-        {
-          state: 'PA',
-          births: 16661910,
-          popular_name: 'Isabella',
-          prev_births_by_name: 21467359,
-        },
-        {
-          state: 'IL',
-          births: 15178876,
-          popular_name: 'Isabella',
-          prev_births_by_name: 16661910,
-        },
-        {
-          state: 'OH',
-          births: 14201526,
-          popular_name: 'Isabella',
-          prev_births_by_name: 15178876,
-        },
-        {
-          state: 'MI',
-          births: 11643455,
-          popular_name: 'Sophia',
-          prev_births_by_name: null,
-        },
-        {
-          state: 'FL',
-          births: 9277223,
-          popular_name: 'Isabella',
-          prev_births_by_name: 14201526,
-        },
-        {
-          state: 'NC',
-          births: 8440235,
-          popular_name: 'Emma',
-          prev_births_by_name: null,
-        },
-        {
-          state: 'NJ',
-          births: 8318769,
-          popular_name: 'Isabella',
-          prev_births_by_name: 9277223,
-        },
       ]);
     });
   });