[material_ui] Migrate M3 Typography template to use new gen_defaults by ValentinVignal · Pull Request #13074 · flutter/packages

ValentinVignal · 2026-09-30T15:24:39Z

Work toward flutter/flutter#187899.
Fixes flutter/flutter#188440

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ValentinVignal · 2026-09-30T15:25:20Z

I guess, like the other PRs migrating to use the new gen_defaults, this doesn't require a version and changelog

gemini-code-assist

Code Review

This pull request migrates the Material 3 typography defaults generation to a dedicated template (TypographyTemplateM3) and outputs them to a generated file (typography_defaults_m3.g.dart), which is then included as a part of typography.dart. Feedback on these changes highlights two critical issues: first, typography.dart still references the old _M3Typography class name instead of the renamed _TypographyDefaultsM3, which will cause compilation errors; second, the newly added test in gen_defaults_test.dart incorrectly asserts the presence of the old class name and needs to be updated to match the new class name.

gemini-code-assist · 2026-09-30T15:27:02Z

 import 'colors.dart';
 import 'text_theme.dart';

+part 'generated/typography_defaults_m3.g.dart';


The generated class name has been changed from _M3Typography to _TypographyDefaultsM3 in typography_defaults_m3.g.dart. However, typography.dart still references _M3Typography (for example, at line 2086: static const TextTheme tall2021 = _M3Typography.tall;, and likely for englishLike2021 and dense2021 as well). This will cause compilation errors. Please update all references in typography.dart to use _TypographyDefaultsM3 instead of _M3Typography.

See suggestion below, we should keep the _M3Typography name.

gemini-code-assist · 2026-09-30T15:27:02Z

-      // https://github.com/flutter/flutter/issues/187899
+      const template = TypographyTemplateM3();
+      final String contents = _generateContents(template);
+      expect(contents, contains('abstract final class _M3Typography'));


The test expects the generated class to be named _M3Typography, but the new TypographyTemplateM3 generates _TypographyDefaultsM3 (as seen in the generated file). This will cause the test to fail. Please update the assertion to expect _TypographyDefaultsM3.

Suggested change

expect(contents, contains('abstract final class _M3Typography'));

expect(contents, contains('abstract final class _TypographyDefaultsM3'));

QuncCccccc

I guess, like the other PRs migrating to use the new gen_defaults, this doesn't require a version and changelog

Yes! I added the no version and no changelog label. Thanks a lot for your contribution!

I noticed this PR has some non-trypography change. We might want to revert them. Also could you help fixing all the test failures?

elliette

Thank you! Was about to open a PR for this then saw you had gotten to it first 😄 Left a couple comments but overall looks good!

elliette · 2026-10-01T22:14:58Z

  /// The Material Design 3 specification does not include 'dense' text themes,
  /// so this is just here to be consistent with the API.
-  static const TextTheme dense2021 = _M3Typography.dense;
+  static const TextTheme dense2021 = _TypographyDefaultsM3.dense;


To keep the naming consistent, please override the className getter in the template, see main...elliette:packages:migrate-typography#diff-cd387c1377e5fd1f1de9eda3032a1ebb418be74300b8cdb0b92d595fbcc54352R18.

Sure, I renamed it in Rename to _M3Typography

elliette · 2026-10-01T22:15:37Z

 import 'colors.dart';
 import 'text_theme.dart';

+part 'generated/typography_defaults_m3.g.dart';


See suggestion below, we should keep the _M3Typography name.

elliette · 2026-10-01T22:16:59Z

+}
+''';
+
+  String _textTheme(String name, String baseline) {


We can do this in a loop, see example in main...elliette:packages:migrate-typography#diff-cd387c1377e5fd1f1de9eda3032a1ebb418be74300b8cdb0b92d595fbcc54352R53

Nice! I've copied it in Use loop

# Conflicts: # packages/material_ui/tool/gen_defaults/bin/gen_defaults.dart # packages/material_ui/tool/gen_defaults/test/gen_defaults_test.dart # Conflicts: # packages/material_ui/tool/gen_defaults/bin/gen_defaults.dart # packages/material_ui/tool/gen_defaults/test/gen_defaults_test.dart

QuncCccccc

LGTM. Thank you for the migration:)!

@example

flutter/packages@7660d46...54706bd 2026-10-08 [email protected] [image_picker_ios] Return an error for undecodable image data (flutter/packages#12267) 2026-10-07 [email protected] [flutter shaders] update min flutter version (flutter/packages#13160) 2026-10-07 [email protected] Import flutter_shaders package (flutter/packages#12583) 2026-10-07 [email protected] [material_ui] Migrate M3 Typography template to use new gen_defaults (flutter/packages#13074) 2026-10-07 [email protected] Sync release-material_ui-1.6.0 to main (flutter/packages#13149) 2026-10-07 [email protected] [pigeon] Fix native interop (JNI) calls in minified Android release builds (flutter/packages#13151) 2026-10-06 [email protected] [material_ui] Migrate ListTile and SwitchListTile API doc snippets to {@example} (batch 10) (flutter/packages#13097) 2026-10-06 [email protected] Sync release-cupertino_ui-1.1.2 to main (flutter/packages#13150) 2026-10-06 [email protected] [material_ui] Fix `TabBar` assertion to allow `indicatorWeight: 0` with a themed `indicator` (flutter/packages#12696) 2026-10-06 [email protected] [material_ui] Fix time picker input validation for 24-hour locales (flutter/packages#13033) 2026-10-06 [email protected] [material_ui] Migrate Checkbox, CheckboxListTile, Radio, and RadioListTile API doc snippets to {@example} (batch 9) (flutter/packages#13112) 2026-10-06 [email protected] [quick_actions_android] Return null from getLaunchAction when no activity is attached (flutter/packages#12331) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages-flutter-autoroll Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

@example

flutter/packages@7660d46...54706bd 2026-10-08 [email protected] [image_picker_ios] Return an error for undecodable image data (flutter/packages#12267) 2026-10-07 [email protected] [flutter shaders] update min flutter version (flutter/packages#13160) 2026-10-07 [email protected] Import flutter_shaders package (flutter/packages#12583) 2026-10-07 [email protected] [material_ui] Migrate M3 Typography template to use new gen_defaults (flutter/packages#13074) 2026-10-07 [email protected] Sync release-material_ui-1.6.0 to main (flutter/packages#13149) 2026-10-07 [email protected] [pigeon] Fix native interop (JNI) calls in minified Android release builds (flutter/packages#13151) 2026-10-06 [email protected] [material_ui] Migrate ListTile and SwitchListTile API doc snippets to {@example} (batch 10) (flutter/packages#13097) 2026-10-06 [email protected] Sync release-cupertino_ui-1.1.2 to main (flutter/packages#13150) 2026-10-06 [email protected] [material_ui] Fix `TabBar` assertion to allow `indicatorWeight: 0` with a themed `indicator` (flutter/packages#12696) 2026-10-06 [email protected] [material_ui] Fix time picker input validation for 24-hour locales (flutter/packages#13033) 2026-10-06 [email protected] [material_ui] Migrate Checkbox, CheckboxListTile, Radio, and RadioListTile API doc snippets to {@example} (batch 9) (flutter/packages#13112) 2026-10-06 [email protected] [quick_actions_android] Return null from getLaunchAction when no activity is attached (flutter/packages#12331) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages-flutter-autoroll Please CC [email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Flutter: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

flutter-dashboard Bot added the CICD Run CI/CD label Sep 30, 2026

github-actions Bot added p: material_ui triage-design Should be looked at in design triage labels Sep 30, 2026

gemini-code-assist Bot reviewed Sep 30, 2026

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QuncCccccc added override: no versioning needed Override the check requiring version bumps for most changes override: no changelog needed Override the check requiring CHANGELOG updates for most changes labels Sep 30, 2026

QuncCccccc reviewed Sep 30, 2026

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ValentinVignal force-pushed the material-ui/Move-typography-template-out-of-temporarily-excluded-directory branch from 8f1ec29 to 95eced6 Compare October 1, 2026 06:56

elliette reviewed Oct 1, 2026

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QuncCccccc added the waiting for response The Flutter team cannot make further progress on this PR until the author responds label Oct 2, 2026

ValentinVignal added 8 commits October 6, 2026 14:37

Move template/generated code out of temporarily_excluded directory

e987ea6

Revert non typography files

67917e8

Fix linter and test

bc83d70

Fix tests

5245bd4

Rename to _M3Typography

1fa90c9

Use loop

48679ca

Update tests

b8e53e6

ValentinVignal force-pushed the material-ui/Move-typography-template-out-of-temporarily-excluded-directory branch from 7451360 to b8e53e6 Compare October 6, 2026 06:49

ValentinVignal requested review from QuncCccccc and elliette October 6, 2026 06:55

github-actions Bot removed the waiting for response The Flutter team cannot make further progress on this PR until the author responds label Oct 6, 2026

QuncCccccc approved these changes Oct 7, 2026

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QuncCccccc added the autosubmit Merge PR when tree becomes green via auto submit App label Oct 7, 2026

auto-submit Bot merged commit 05aaa04 into flutter:main Oct 7, 2026
13 checks passed

	expect(contents, contains('abstract final class _M3Typography'));
	expect(contents, contains('abstract final class _TypographyDefaultsM3'));

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