fixup! fix(material/tabs): allow both foreground and background colors to be set (#26212)

Author: wagnermaciel

src/material/schematics/ng-generate/mdc-migration/rules/tree-traversal.spec.ts

@@ -190,6 +190,41 @@ describe('#visitElements', () => {
     it('should add value to existing attribute that does not have a value', async () => {
       runAddAttributeTest('<a add></a>', '<a add="val"></a>');
     });
+
+    it('should handle all forms of indentation', async () => {
+      runAddAttributeTest(
+        '<a *ngFor="let item of items">',
+        '<a add="val" *ngFor="let item of items">',
+      );
+      runAddAttributeTest(
+        `
+        <a
+          *ngFor="let item of items">`,
+        `
+        <a
+          add="val"
+          *ngFor="let item of items">`,
+      );
+      runAddAttributeTest(
+        `
+        <a *ngFor="let item of items"
+        >`,
+        `
+        <a add="val" *ngFor="let item of items"
+        >`,
+      );
+      runAddAttributeTest(
+        `
+        <a
+          [attr]="
+          val">`,
+        `
+        <a
+          add="val"
+          [attr]="
+          val">`,
+      );
+    });
   });
 
   describe('remove attribute tests', () => {

src/material/schematics/ng-generate/mdc-migration/rules/tree-traversal.ts

@@ -163,14 +163,24 @@ export function updateAttribute(
     return `${prefix} ${attrText}${suffix}`;
   }
 
-  const binding = node.attributes[0] ?? node.inputs[0] ?? node.outputs[0];
-  if (binding) {
-    const ctx = binding.sourceSpan.start.getContext(binding.sourceSpan.start.col + 1, 1)!;
-    const indentation = ctx.before;
-    return prefix + indentation + attrText + suffix;
-  }
+  const indentation = parseIndentation(html, node);
+  return prefix + indentation + attrText + suffix;
+}
+
+function parseIndentation(html: string, node: TmplAstElement): string {
+  let whitespace = '';
+  let startOffset = node.startSourceSpan.start.offset + node.name.length + 1;
 
-  return prefix + attrText + suffix;
+  // Starting after the start source span's tagname,
+  // read and store each char until we reach a non-whitespace char.
+
+  for (let i = startOffset; i < html.length - 1; i++) {
+    if (!/\s/.test(html.charAt(i))) {
+      break;
+    }
+    whitespace += html.charAt(i);
+  }
+  return whitespace;
 }
 
 /**