fix(ivy): include `ngProjectAs` into attributes array (#32784)

Prior to this commit, the `ngProjectAs` attribute was only included with a special flag and in a parsed format. As a result, projected node was missing `ngProjectAs` attribute as well as other attributes added after `ngProjectAs` one. This is problematic since app code might rely on the presence of `ngProjectAs` attribute (for example in CSS). This commit fixes the problem by including `ngProjectAs` into attributes array as a regular attribute and also makes sure that the parsed version of the `ngProjectAs` attribute with a special marker is added after regular attributes (thus we set them correctly at runtime). This change also aligns View Engine and Ivy behavior.

PR Close #32784

packages/compiler-cli/test/compliance/r3_compiler_compliance_spec.ts

@@ -1376,7 +1376,7 @@ describe('compiler compliance', () => {
         const SimpleComponentDefinition = `
           const $_c0$ = [[["", "title", ""]]];
           const $_c1$ = ["[title]"];
-          const $_c2$ = [5, ["", "title", ""]];
+          const $_c2$ = ["ngProjectAs", "[title]", 5, ["", "title", ""]];
           …
           MyApp.ngComponentDef = $r3$.ɵɵdefineComponent({
             type: MyApp,
@@ -1428,7 +1428,7 @@ describe('compiler compliance', () => {
         const SimpleComponentDefinition = `
           const $_c0$ = [[["", "title", ""]]];
           const $_c1$ = ["[title]"];
-          const $_c2$ = [5, ["", "title", ""]];
+          const $_c2$ = ["ngProjectAs", "[title],[header]", 5, ["", "title", ""]];
           …
           MyApp.ngComponentDef = $r3$.ɵɵdefineComponent({
             type: MyApp,

packages/compiler/src/render3/view/template.ts

@@ -497,18 +497,24 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
     const projectionSlotIdx = this._ngContentSelectorsOffset + this._ngContentReservedSlots.length;
     const parameters: o.Expression[] = [o.literal(slot)];
     const attributes: o.Expression[] = [];
+    let ngProjectAsAttr: t.TextAttribute|undefined;
 
     this._ngContentReservedSlots.push(ngContent.selector);
 
     ngContent.attributes.forEach((attribute) => {
       const {name, value} = attribute;
       if (name === NG_PROJECT_AS_ATTR_NAME) {
-        attributes.push(...getNgProjectAsLiteral(attribute));
+        ngProjectAsAttr = attribute;
-      } else if (name.toLowerCase() !== NG_CONTENT_SELECT_ATTR) {
+      }
+      if (name.toLowerCase() !== NG_CONTENT_SELECT_ATTR) {
         attributes.push(o.literal(name), o.literal(value));
       }
     });
 
+    if (ngProjectAsAttr) {
+      attributes.push(...getNgProjectAsLiteral(ngProjectAsAttr));
+    }
+
     if (attributes.length > 0) {
       parameters.push(o.literal(projectionSlotIdx), o.literalArr(attributes));
     } else if (projectionSlotIdx !== 0) {
@@ -535,6 +541,7 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
 
     const i18nAttrs: (t.TextAttribute | t.BoundAttribute)[] = [];
     const outputAttrs: t.TextAttribute[] = [];
+    let ngProjectAsAttr: t.TextAttribute|undefined;
 
     const [namespaceKey, elementName] = splitNsName(element.name);
     const isNgContainer = checkIsNgContainer(element.name);
@@ -549,6 +556,9 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
       } else if (name === 'class') {
         stylingBuilder.registerClassAttr(value);
       } else {
+        if (attr.name === NG_PROJECT_AS_ATTR_NAME) {
+          ngProjectAsAttr = attr;
+        }
         if (attr.i18n) {
           // Place attributes into a separate array for i18n processing, but also keep such
           // attributes in the main list to make them available for directive matching at runtime.
@@ -590,16 +600,12 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
     });
 
     outputAttrs.forEach(attr => {
-      if (attr.name === NG_PROJECT_AS_ATTR_NAME) {
+      attributes.push(...getAttributeNameLiterals(attr.name), o.literal(attr.value));
-        attributes.push(...getNgProjectAsLiteral(attr));
-      } else {
-        attributes.push(...getAttributeNameLiterals(attr.name), o.literal(attr.value));
-      }
     });
 
     // add attributes for directive and projection matching purposes
     attributes.push(...this.prepareNonRenderAttrs(
-        allOtherInputs, element.outputs, stylingBuilder, [], i18nAttrs));
+        allOtherInputs, element.outputs, stylingBuilder, [], i18nAttrs, ngProjectAsAttr));
     parameters.push(this.toAttrsParam(attributes));
 
     // local refs (ex.: <div #foo #bar="baz">)
@@ -1206,6 +1212,7 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
    *   STYLES, style1, value1, style2, value2,
    *   BINDINGS, name1, name2, name3,
    *   TEMPLATE, name4, name5, name6,
+   *   PROJECT_AS, selector,
    *   I18N, name7, name8, ...]
    * ```
    *
@@ -1215,7 +1222,8 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
   private prepareNonRenderAttrs(
       inputs: t.BoundAttribute[], outputs: t.BoundEvent[], styles?: StylingBuilder,
       templateAttrs: (t.BoundAttribute|t.TextAttribute)[] = [],
-      i18nAttrs: (t.BoundAttribute|t.TextAttribute)[] = []): o.Expression[] {
+      i18nAttrs: (t.BoundAttribute|t.TextAttribute)[] = [],
+      ngProjectAsAttr?: t.TextAttribute): o.Expression[] {
     const alreadySeen = new Set<string>();
     const attrExprs: o.Expression[] = [];
 
@@ -1271,6 +1279,10 @@ export class TemplateDefinitionBuilder implements t.Visitor<void>, LocalResolver
       templateAttrs.forEach(attr => addAttrExpr(attr.name));
     }
 
+    if (ngProjectAsAttr) {
+      attrExprs.push(...getNgProjectAsLiteral(ngProjectAsAttr));
+    }
+
     if (i18nAttrs.length) {
       attrExprs.push(o.literal(core.AttributeMarker.I18n));
       i18nAttrs.forEach(attr => addAttrExpr(attr.name));

packages/core/test/acceptance/content_spec.ts

@@ -1025,6 +1025,36 @@ describe('projection', () => {
     expect(fixture.nativeElement.textContent).not.toContain('Title content');
   });
 
+  it('should preserve ngProjectAs and other attributes on projected element', () => {
+    @Component({
+      selector: 'projector',
+      template: `<ng-content select="projectMe"></ng-content>`,
+    })
+    class Projector {
+    }
+
+    @Component({
+      template: `
+        <projector>
+          <div ngProjectAs="projectMe" title="some title"></div>
+        </projector>
+      `
+    })
+    class Root {
+    }
+
+    TestBed.configureTestingModule({
+      declarations: [Root, Projector],
+    });
+    const fixture = TestBed.createComponent(Root);
+    fixture.detectChanges();
+
+    const projectedElement = fixture.debugElement.query(By.css('div'));
+    const {ngProjectAs, title} = projectedElement.attributes;
+    expect(ngProjectAs).toBe('projectMe');
+    expect(title).toBe('some title');
+  });
+
   describe('on inline templates (e.g.  *ngIf)', () => {
     it('should work when matching the element name', () => {
       let divDirectives = 0;