fix(core): migrating input with more than 1 usage in a method

When the migration command was run for inputs, if the input had more than one reference in a method the migration would generate incorrect code

Fixes #63018

Author: aparzi

packages/core/schematics/migrations/signal-migration/src/passes/reference_migration/helpers/standard_reference.ts

@@ -124,18 +124,44 @@ export function migrateStandardTsReference(
           ...createNewBlockToInsertVariable(parent, filePath, temporaryVariableStr),
         );
       } else {
-        const leadingSpace = ts.getLineAndCharacterOfPosition(sf, referenceNodeInBlock.getStart());
-
-        replacements.push(
-          new Replacement(
-            filePath,
-            new TextUpdate({
-              position: referenceNodeInBlock.getStart(),
-              end: referenceNodeInBlock.getStart(),
-              toInsert: `${temporaryVariableStr}\n${' '.repeat(leadingSpace.character)}`,
-            }),
-          ),
-        );
+        // If parent is a Block, insert the temporary variable at the beginning of the block.
+        if (
+          ts.isBlock(recommendedNode) &&
+          shouldInsertAtMethodStart(reference, recommendedNode, referenceNodeInBlock)
+        ) {
+          const blockStart = recommendedNode.getStart() + 1;
+          const firstStatement = recommendedNode.statements[0];
+          const leadingSpace = firstStatement
+            ? ts.getLineAndCharacterOfPosition(sf, firstStatement.getStart())
+            : ts.getLineAndCharacterOfPosition(sf, referenceNodeInBlock.getStart());
+
+          replacements.push(
+            new Replacement(
+              filePath,
+              new TextUpdate({
+                position: blockStart,
+                end: blockStart,
+                toInsert: `\n${' '.repeat(leadingSpace.character)}${temporaryVariableStr}\n${' '.repeat(leadingSpace.character)}`,
+              }),
+            ),
+          );
+        } else {
+          const leadingSpace = ts.getLineAndCharacterOfPosition(
+            sf,
+            referenceNodeInBlock.getStart(),
+          );
+
+          replacements.push(
+            new Replacement(
+              filePath,
+              new TextUpdate({
+                position: referenceNodeInBlock.getStart(),
+                end: referenceNodeInBlock.getStart(),
+                toInsert: `${temporaryVariableStr}\n${' '.repeat(leadingSpace.character)}`,
+              }),
+            ),
+          );
+        }
       }
 
       replacements.push(
@@ -151,3 +177,32 @@ export function migrateStandardTsReference(
     }
   }
 }
+
+function shouldInsertAtMethodStart(
+  references: NarrowableTsReferences,
+  recommendedNode: ts.Node,
+  referenceNodeInBlock: ts.Node,
+): boolean {
+  // Check if the recommended node is a method declaration
+  if (!ts.isBlock(recommendedNode) || !ts.isMethodDeclaration(recommendedNode.parent)) {
+    return false;
+  }
+
+  // Check all references are within the method body
+  const methodBody = recommendedNode;
+  const allReferencesInMethod = references.accesses.every((access) => {
+    let current: ts.Node | undefined = access;
+    while (current && current !== methodBody) {
+      current = current.parent;
+    }
+    return current === methodBody;
+  });
+
+  if (!allReferencesInMethod) {
+    return false;
+  }
+
+  // Verify that referenceNodeInBlock is the first statement of the method
+  // or at least that no temporary variable has been created before it
+  return methodBody.statements.length > 0 && methodBody.statements[0] === referenceNodeInBlock;
+}

packages/core/schematics/test/signals_migration_spec.ts

@@ -122,4 +122,52 @@ describe('combined signals migration', () => {
     `),
     );
   });
+
+  it('should be able to migrate input with more than 1 usage in a method', async () => {
+    writeFile(
+      '/index.ts',
+      `
+      import {Component, Input} from '@angular/core';
+
+      @Component({
+        template: 'it works'
+      })
+      export class TestMigrationComponent {
+        @Input() public model: any;
+
+        public onSaveClick(): void {
+            this.model.requisitionId = 145;
+            this.model.comment = 'value';
+            this.model.status = 8;
+            this.model.finilizeReasonId = 4
+        }
+      }`,
+    );
+
+    await runMigration(['inputs']);
+
+    expect(stripWhitespace(tree.readContent('/index.ts'))).toBe(
+      stripWhitespace(
+        `
+      import {Component, input} from '@angular/core';
+
+      @Component({
+        template: 'it works'
+      })
+      export class TestMigrationComponent {
+        public readonly model = input<any>(undefined);
+
+        public onSaveClick(): void {
+            const model = this.model();
+
+            model.requisitionId = 145;
+            model.comment = 'value';
+            model.status = 8;
+            model.finilizeReasonId = 4
+        }
+      }
+    `,
+      ),
+    );
+  });
 });