fix: parse field projections after encodings to prevent duplicates (#…

…7164)
vega · Jan 7, 2021 · f365e1f · f365e1f
1 parent bafca07
commit f365e1f
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Showing 2 changed files with 23 additions and 8 deletions.
diff --git a/src/compile/selection/project.ts b/src/compile/selection/project.ts
@@ -96,14 +96,6 @@ const project: SelectionCompiler = {
       }
     }
 
-    // TODO: find a possible channel mapping for these fields.
-    for (const field of fields ?? []) {
-      const p: SelectionProjection = {type: 'E', field};
-      p.signals = {...signalName(p, 'data')};
-      proj.items.push(p);
-      proj.hasField[field] = p;
-    }
-
     for (const channel of encodings ?? []) {
       const fieldDef = model.fieldDef(channel);
       if (fieldDef) {
@@ -158,6 +150,15 @@ const project: SelectionCompiler = {
       }
     }
 
+    // TODO: find a possible channel mapping for these fields.
+    for (const field of fields ?? []) {
+      if (proj.hasField[field]) continue;
+      const p: SelectionProjection = {type: 'E', field};
+      p.signals = {...signalName(p, 'data')};
+      proj.items.push(p);
+      proj.hasField[field] = p;
+    }
+
     if (init) {
       selCmpt.init = (init as any).map((v: SelectionInitMapping | SelectionInitIntervalMapping) => {
         return proj.items.map(p => (v[p.channel] !== undefined ? v[p.channel] : v[p.field]));

diff --git a/test/compile/selection/parse.test.ts b/test/compile/selection/parse.test.ts
@@ -282,6 +282,20 @@ describe('Selection', () => {
         }
       ]);
     });
+
+    it('does not add duplicate projections', () => {
+      const component = parseUnitSelection(model, [
+        {
+          name: 'one',
+          select: {type: 'interval', fields: ['Horsepower', 'Miles_per_Gallon'], encodings: ['x', 'y']}
+        }
+      ]);
+
+      expect(component['one'].project.items).toEqual([
+        {field: 'Horsepower', channel: 'x', type: 'R', signals: {data: 'one_Horsepower', visual: 'one_x'}},
+        {field: 'Miles_per_Gallon', channel: 'y', type: 'R', signals: {data: 'one_Miles_per_Gallon', visual: 'one_y'}}
+      ]);
+    });
   });
 
   it('materializes a selection', () => {