From b3a21c302d7a44c35e17b7f3c8f60609fa90712d Mon Sep 17 00:00:00 2001
From: Jessica Janiuk <jessicajaniuk@google.com>
Date: Mon, 27 Nov 2023 14:15:15 -0500
Subject: [PATCH] fix(migrations): fixes CF migration i18n ng-template offsets

This addresses an issue where multiple ng-templates are present with i18n attributes. The offsets would be incorrectly accounted for when being replaced with an ng-container.

fixes: #53149
---
 .../control-flow-migration/util.ts            | 11 ++--
 .../test/control_flow_migration_spec.ts       | 52 ++++++++++---------
 2 files changed, 35 insertions(+), 28 deletions(-)

diff --git a/packages/core/schematics/ng-generate/control-flow-migration/util.ts b/packages/core/schematics/ng-generate/control-flow-migration/util.ts
index c3cd8c202966fd..51f4b91fc8de1a 100644
--- a/packages/core/schematics/ng-generate/control-flow-migration/util.ts
+++ b/packages/core/schematics/ng-generate/control-flow-migration/util.ts
@@ -302,8 +302,14 @@ export function getTemplates(template: string): Map<string, Template> {
 }
 
 function wrapIntoI18nContainer(i18nAttr: Attribute, content: string) {
+  const {start, middle, end} = generatei18nContainer(i18nAttr, content);
+  return `${start}${middle}${end}`;
+}
+
+function generatei18nContainer(
+    i18nAttr: Attribute, middle: string): {start: string, middle: string, end: string} {
   const i18n = i18nAttr.value === '' ? 'i18n' : `i18n="${i18nAttr.value}"`;
-  return `<ng-container ${i18n}>${content}</ng-container>`;
+  return {start: `<ng-container ${i18n}>`, middle, end: `</ng-container>`};
 }
 
 /**
@@ -427,8 +433,7 @@ export function getMainBlock(etm: ElementToMigrate, tmpl: string, offset: number
   } else if (isI18nTemplate(etm, i18nAttr)) {
     const childStart = etm.el.children[0].sourceSpan.start.offset - offset;
     const childEnd = etm.el.children[etm.el.children.length - 1].sourceSpan.end.offset - offset;
-    const middle = wrapIntoI18nContainer(i18nAttr!, tmpl.slice(childStart, childEnd));
-    return {start: '', middle, end: ''};
+    return generatei18nContainer(i18nAttr!, tmpl.slice(childStart, childEnd));
   }
 
   const attrStart = etm.attr.keySpan!.start.offset - 1 - offset;
diff --git a/packages/core/schematics/test/control_flow_migration_spec.ts b/packages/core/schematics/test/control_flow_migration_spec.ts
index e731b7835c2364..2867b229a26652 100644
--- a/packages/core/schematics/test/control_flow_migration_spec.ts
+++ b/packages/core/schematics/test/control_flow_migration_spec.ts
@@ -620,9 +620,9 @@ describe('control flow migration', () => {
       ].join('\n'));
     });
 
-    fit('should migrate an NgIfElse case with ng-templates with multiple i18n attributes',
-        async () => {
-          writeFile('/comp.ts', `
+    it('should migrate an NgIfElse case with ng-templates with multiple i18n attributes',
+       async () => {
+         writeFile('/comp.ts', `
         import {Component} from '@angular/core';
         import {NgIf} from '@angular/common';
 
@@ -634,28 +634,30 @@ describe('control flow migration', () => {
         }
       `);
 
-          writeFile('/comp.html', [
-            `<ng-template *ngIf="false; else barTempl" i18n="@@foo">`,
-            `  Foo`,
-            `</ng-template>`,
-            `<ng-template i18n="@@bar" #barTempl> Bar </ng-template>`,
-            `<a *ngIf="true" i18n="@@bam">Bam</a>`,
-          ].join('\n'));
-
-          await runMigration();
-          const content = tree.readContent('/comp.html');
-
-          expect(content).toBe([
-            `@if (false) {`,
-            `  <ng-container i18n="@@foo">Foo</ng-container>`,
-            `} @else {`,
-            `  <ng-container i18n="@@bar"> Bar </ng-container>`,
-            `}`,
-            `@if (true) {`,
-            `  <a i18n="@@bam">Bam</a>`,
-            `}`,
-          ].join('\n'));
-        });
+         writeFile('/comp.html', [
+           `<ng-template *ngIf="false; else barTempl" i18n="@@foo">`,
+           `  Foo`,
+           `</ng-template>`,
+           `<ng-template i18n="@@bar" #barTempl> Bar </ng-template>`,
+           `<a *ngIf="true" i18n="@@bam">Bam</a>`,
+         ].join('\n'));
+
+         await runMigration();
+         const content = tree.readContent('/comp.html');
+
+         expect(content).toBe([
+           `@if (false) {`,
+           `  <ng-container i18n="@@foo">`,
+           `    Foo`,
+           `  </ng-container>`,
+           `} @else {`,
+           `  <ng-container i18n="@@bar"> Bar </ng-container>`,
+           `}`,
+           `@if (true) {`,
+           `  <a i18n="@@bam">Bam</a>`,
+           `}`,
+         ].join('\n'));
+       });
 
     it('should migrate an if else case', async () => {
       writeFile('/comp.ts', `