As a part of #54154, an old parser behavior came up where two-way bindings were parsed by appending `= $event` to the event side. This was problematic, because it allowed some non-writable expressions to be passed into two-way bindings.
These changes introduce a migration that will change the two-way bindings into two separate input/output bindings that represent the old behavior so that in a future version we can throw a parser error for the invalid expressions.
```ts
// Before
@Component({
template: `<input [(ngModel)]="a && b"/>`
})
export class MyComp {}
// After
@Component({
template: `<input [ngModel]="a && b" (ngModelChange)="a && (b = $event)"/>`
})
export class MyComp {}
```
PR Close#54630
Fixes an edge case where a single-line elemnt with a long tag name a closing bracket on a new line was putting the control flow migration into an infinite loop.
Fixes#54587.
PR Close#54588
In rare cases people may use an underscore in their component names, which was not accounted for in the formatting portion of the migration.
fixes: #54532
PR Close#54533
Adds some logic to skip over `TestBed.configureTestingModule` calls where the `declarations` aren't initialized to an array. We can't migrate these cases, because test migrations don't have access to the Angular compiler. Previously the migration would throw a runtime error.
PR Close#54122
This addresses the offset issue caused when a switch case was empty with no spaces or children being affected by the markers that were added, but not accounted for in offset. The markers are not needed for empty content and can be safely removed in this case.
fixes: #53779
PR Close#53839
The formatting that would preserve attribute indents completely missed attributes that start on new lines rather than the same line as the opening element.
PR Close#53636
In cases where CommonModule was unsafe to remove but other imports were present, the symbol check would be skipped. This should run for all the possibly removed symbols for safety.
PR Close#53637
During formatting, attribute indentation is changed, and that can affect internationalized strings. This fix detects if an attribute value string is left open and skips formatting on those lines.
PR Close#53625
This addresses the case where modules are being used and declared in the same file as the component. It is unclear whether its safe to remove the common module in this case, so best to leave it.
PR Close#53575
Internationalization is whitespace sensitive. This change updates the formatting code to process for i18n attributes and prevent reformatting those sections of the template.
PR Close#53538
This fix handles the common case where an ngswitch might have invalid syntax post migration. This is likely due to using elements other than case or default underneath the ngswitchcase. This will fail out of the migration for that file when these cases are detected with a useful console message.
fixes: #53234
PR Close#53530
In the case that a template has some sort of structural issue prior to migrating, like a tag that is not properly closed resulting in invalid HTML post migration, this will attempt to parse the html after migrating and revert to the original structure. An error during migration will be reported out instead.
PR Close#53530
The formatting logic would eliminate all newlines in updated template code. This adds start and end markers for tracking when the formatter is in a block of template code that changed or not. It should leave behind any newlines that are outside of a migrated section.
fixes: #53494
PR Close#53508
When migrating a component and the associated external template, if errors occur, the component should not remove the common module imports. This fix should allow the application to still build in that instance.
PR Close#53502
When using ternaries or other expressions in bound if / else cases, it is possible that line breaks could end up affecting template replacement.
fixes: #53428
PR Close#53435
Using more unique characters makes it easier to parse placeholders that may contain JS logic, making it more flexible.
fixes: #53386fixes: #53385fixes: #53384
PR Close#53394
If a template is passed in as an input, the ng-template will not exist in the same component template. This will leave a template placeholder behind. This fix ensures that template placeholder gets turned into a template outlet.
fixes: #53361
PR Close#53368
When there are ng-templates nested inside other ng-templates, the replacement and removal of the templates gets disrupted. Re-processing the templates in the file along the way resolves this issue.
fixes: #53362
PR Close#53368
This setting was added to prevent comment duplication, since the TS AST printer includes prior line comments as part of a given line with no way to really avoid that.
However in component imports, it is not safe to remove comments as they could be load bearing for some.
PR Close#53350
Prior to this fix, the expectation that anytime then was used, else would always be present. That is not a valid assumption.
fixes: #53287
PR Close#53297
i18n template removal expected no other attributes to be present, but if a bound ngIf is present with aliases and i18n, that is more than what was expected. Now it should safely remove them appropriately.
fixes: #53289
PR Close#53299
The regexp for then and else did not ignore alphanumeric characters prior to the then and else. So if a string contained then, for example Authentication, it would incorrectly match as a then clause.
fixes: #53252
PR Close#53257
When ng-templates are removed, an extra space was being added when it was unnecessary. This resulted in malformed html if there was no space afterwards.
fixes: #53248
PR Close#53255
This should address cases when using ng-containers with ngSwitchCase / ngSwitchDefault
and migrating them safely when they are empty.
fixes: #53235
PR Close#53237
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
PR Close#53212
Common module removal would not happen when a component used a templateUrl due to the checks being in separate files. This change passes the removal analysis back to the original source file to safely remove CommonModule.
PR Close#53076
This separates out the NgSwitch migration pass from the NgSwitchCase / Default pass, which makes nested switch migrations work.
fixes: #53009
PR Close#53010
With if then else use cases, we now properly account for the length
of the original element's contents when tracking new offsets.
fixes: #52927
PR Close#53006
