Introduce conversion between chrono::NaiveDate and DateTime avoiding RustOpaque

[TrackerSB]

Changes

Fixes #1833

Procedure and Checklist

In order to quickly iterate and avoid slowing down development pace by making CI pass, only the following simplified steps are needed, and I (fzyzcjy) will handle the rest of CI / moving the tests currently (will have more automation in the future).

• Implement the feature / fix the bug.
• Add tests in frb_example/dart_minimal.
• Make dart_minimal's CI green.

Utility commands

• Run codegen: cargo run --manifest-path /path/to/flutter_rust_bridge/frb_codegen/Cargo.toml -- generate
• Run tests: ./frb_internal test-dart-native --package frb_example/dart_minimal

[TrackerSB]

As far as I can see meanwhile (since my last attempt) the PR template changed in the way that I should have made an example in dart_minimal.
Unknowingly, I added the implementation and the tests in dart_pure and generated all the other variants. At least I guess I did that.

[codecov]

Codecov Report

❌ Patch coverage is 86.44068% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.75%. Comparing base (7ce1020) to head (eaf057c).

Files with missing lines	Patch %	Lines
...st/spec_generator/codec/cst/decoder/ty/delegate.rs	0.00%	2 Missing ⚠️
frb_dart/lib/src/misc/rust_opaque.dart	33.33%	2 Missing ⚠️
...rt/spec_generator/codec/cst/encoder/ty/delegate.rs	0.00%	1 Missing ⚠️
frb_dart/lib/src/cli/build_web/executor.dart	66.66%	1 Missing ⚠️
frb_dart/lib/src/codec/dco.dart	0.00%	1 Missing ⚠️
frb_dart/test/typed_data_test.dart	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2968      +/-   ##
==========================================
- Coverage   98.34%   90.75%   -7.60%     
==========================================
  Files         470      470              
  Lines       19428    18025    -1403     
==========================================
- Hits        19106    16358    -2748     
- Misses        322     1667    +1345     

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[fzyzcjy]

As far as I can see meanwhile (since my last attempt) the PR template changed in the way that I should have made an example in dart_minimal.
Unknowingly, I added the implementation and the tests in dart_pure and generated all the other variants. At least I guess I did that.

It is better to directly add things in pure_dart etc! :)

[TrackerSB]

I recognized that the regeneration of files resulted in automatically added explicit lifetime annotations. Is this expected, is it a problem, does it depend on the used Rust version?
Additionally, for some files the year in generated comments changed:

-            VALUE "LegalCopyright", "Copyright (C) 2025 com.example. All rights reserved." "\0"
+            VALUE "LegalCopyright", "Copyright (C) 2026 com.example. All rights reserved." "\0"

[TrackerSB]

What next steps are left for me to do to make this PR worth to be merged?

[fzyzcjy]

I recognized that the regeneration of files resulted in automatically added explicit lifetime annotations. Is this expected, is it a problem, does it depend on the used Rust version?
Additionally, for some files the year in generated comments changed:

Feel free to make a separate PR to firstly update code for these!

What next steps are left for me to do to make this PR worth to be merged?

I am sorry that I am having a very tight deadline recently :( I will try my best to find some time after the ddl to review and merge all pending PRs. At the same time, feel free to use your branch if you need this feature, as long as the critical tests in CI passes then usually the branch is good to use.

[sumitsharansatsangi]

@fzyzcjy , Please give this a release .
Thank you !!

[fzyzcjy]

@sumitsharansatsangi I have added some agent Skills a bit time ago, and plan to let agents help me do some updates to code when I review it. too busy recently but will handle it asap!

[sumitsharansatsangi]

Thanks for assurance, @fzyzcjy !!!

[TrackerSB]

I merged origin/master trying to update my PR.
How to handle problems that arise from files of one of the cargokit submodules like the following?

--- a/frb_example/flutter_via_integrate/rust_builder/cargokit/gradle/plugin.gradle
+++ b/frb_example/flutter_via_integrate/rust_builder/cargokit/gradle/plugin.gradle
@@ -95,7 +95,7 @@ class CargoKitPlugin implements Plugin<Project> {
    private Plugin _findFlutterPlugin(Map projects) {
         for (project in projects) {
             for (plugin in project.value.getPlugins()) {
-                if (plugin.class.name == "com.flutter.gradle.FlutterPlugin" || plugin.class.name == "FlutterPlugin") {
+                if (plugin.class.name == "com.flutter.gradle.FlutterPlugin") {
                     return plugin;
                 }
             }
@@ -132,12 +132,7 @@ class CargoKitPlugin implements Plugin<Project> {
             def jniLibs = project.android.sourceSets.maybeCreate(buildType).jniLibs;
             jniLibs.srcDir(new File(cargoOutputDir))
 
-            def List<String> platforms
-            try {
-                platforms = com.flutter.gradle.FlutterPluginUtils.getTargetPlatforms(project).collect()
-            } catch (Exception ignored) {
-                platforms = plugin.getTargetPlatforms().collect()
-            }
+            def platforms = com.flutter.gradle.FlutterPluginUtils.getTargetPlatforms(project).collect()
 
             // Same thing addFlutterDependencies does in flutter.gradle
             if (buildType == "debug") {
Unhandled exception:
ProcessException: Bad exit code (1). If you want to see extra information, set FRB_DART_RUN_COMMAND_STDERR=1
  Command: /bin/sh -c git diff --exit-code ':(exclude)frb_example/flutter_via_integrate/macos/Flutter/Flutter-Debug.xcconfig' ':(exclude)frb_example/flutter_via_integrate/macos/Flutter/Flutter-Release.xcconfig' ':(exclude)frb_example/flutter_via_integrate/rust/Cargo.lock'
{code}

[fzyzcjy]

hmm I guess maybe try to update the submodule

btw I did plan to add sth like #3051 to make it easier to make CI pass. I have emergent ddl recently and cannot continue though :(

[TrackerSB]

This would be amazing. 👍🏻🏆