[oauth2] Add isClosed and exception handling for closed state to oaut…

[illaz]

Until now there is no way to detect whether an oauth2.Client is closed or not. This PR changes that.

There is now an isClosed field on the oauth2.Client.

A request on a closed client no longer leads to a 'Null check operator used on a null value' error, but instead an http.ClientException is thrown with a meaningful error message.

---

• [x ] I’ve reviewed the contributor guide and applied the relevant portions to this PR.

Contribution guidelines:

• See our contributor guide for general expectations for PRs.
• Larger or significant changes should be discussed in an issue before creating a PR.
• Contributions to our repos should follow the Dart style guide and use dart format.
• Most changes should add an entry to the changelog and may need to rev the pubspec package version.
• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[sigurdm]

Should we just not set httpClient to null in close()? In that way we automatically inherit the close() behavior of the wrapped client...

[illaz]

Should we just not set httpClient to null in close()? In that way we automatically inherit the close() behavior of the wrapped client...

Would also be fine for me. This would at least avoid the 'Null check operator used on a null value' error. I can also implement the isClosed behavior in my own code. It does not have to be included in this PR.

Is it okay to make a fixup commit here? Or should I just amend my existing commit?

[github-actions[bot]]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:bazel_worker	1.1.4	already published at pub.dev
package:benchmark_harness	2.4.0-wip	WIP (no publish necessary)
package:boolean_selector	2.1.2	already published at pub.dev
package:browser_launcher	1.1.3	already published at pub.dev
package:cli_config	0.2.1-wip	WIP (no publish necessary)
package:cli_util	0.5.0-wip	WIP (no publish necessary)
package:clock	1.1.3-wip	WIP (no publish necessary)
package:code_builder	4.11.0	already published at pub.dev
package:coverage	1.15.0	already published at pub.dev
package:csslib	1.0.2	already published at pub.dev
package:extension_discovery	2.1.0	already published at pub.dev
package:file	7.0.2-wip	WIP (no publish necessary)
package:file_testing	3.1.0-wip	WIP (no publish necessary)
package:glob	2.1.3	already published at pub.dev
package:graphs	2.3.3-wip	WIP (no publish necessary)
package:html	0.15.7-wip	WIP (no publish necessary)
package:io	1.1.0-wip	WIP (no publish necessary)
package:json_rpc_2	4.0.0	already published at pub.dev
package:markdown	7.3.1-wip	WIP (no publish necessary)
package:mime	2.0.0	already published at pub.dev
package:oauth2	2.0.5	ready to publish	oauth2-v2.0.5
package:package_config	2.3.0-wip	WIP (no publish necessary)
package:pool	1.5.2	already published at pub.dev
package:process	5.0.5	already published at pub.dev
package:pub_semver	2.2.0	already published at pub.dev
package:pubspec_parse	1.5.1-wip	WIP (no publish necessary)
package:source_map_stack_trace	2.1.3-wip	WIP (no publish necessary)
package:source_maps	0.10.14-wip	WIP (no publish necessary)
package:source_span	1.10.1	already published at pub.dev
package:sse	4.1.8	already published at pub.dev
package:stack_trace	1.12.1	already published at pub.dev
package:stream_channel	2.1.4	already published at pub.dev
package:stream_transform	2.1.2-wip	WIP (no publish necessary)
package:string_scanner	1.4.1	already published at pub.dev
package:term_glyph	1.2.3-wip	WIP (no publish necessary)
package:test_reflective_loader	0.4.0	already published at pub.dev
package:timing	1.0.2	already published at pub.dev
package:unified_analytics	8.0.6	ready to publish	unified_analytics-v8.0.6
package:watcher	1.1.5-wip	WIP (no publish necessary)
package:yaml	3.1.3	already published at pub.dev
package:yaml_edit	2.2.2	already published at pub.dev

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[github-actions[bot]]

PR Health

Breaking changes :heavy_check_mark:

Package	Change	Current Version	New Version	Needed Version	Looking good?
oauth2	None	2.0.3	2.0.5	2.0.3	:heavy_check_mark:

This check can be disabled by tagging the PR with skip-breaking-check.

Changelog Entry :heavy_check_mark:

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

This check can be disabled by tagging the PR with skip-changelog-check.

Coverage :heavy_check_mark:

File	Coverage
pkgs/oauth2/lib/src/client.dart	:green_heart: 95 % :arrow_up: 9 %

This check for test coverage is informational (issues shown here will not fail the PR).

This check can be disabled by tagging the PR with skip-coverage-check.

API leaks :heavy_check_mark:

The following packages contain symbols visible in the public API, but not exported by the library. Export these symbols or remove them from your publicly visible API.

Package	Leaked API symbol	Leaking sources

This check can be disabled by tagging the PR with skip-leaking-check.

License Headers :heavy_check_mark:

// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
no missing headers

All source files should start with a license header.

Unrelated files missing license headers

Files
pkgs/bazel_worker/benchmark/benchmark.dart
pkgs/benchmark_harness/integration_test/perf_benchmark_test.dart
pkgs/boolean_selector/example/example.dart
pkgs/clock/lib/clock.dart
pkgs/clock/lib/src/clock.dart
pkgs/clock/lib/src/default.dart
pkgs/clock/lib/src/stopwatch.dart
pkgs/clock/lib/src/utils.dart
pkgs/clock/test/clock_test.dart
pkgs/clock/test/default_test.dart
pkgs/clock/test/stopwatch_test.dart
pkgs/clock/test/utils.dart
pkgs/coverage/lib/src/coverage_options.dart
pkgs/html/example/main.dart
pkgs/html/lib/dom.dart
pkgs/html/lib/dom_parsing.dart
pkgs/html/lib/html_escape.dart
pkgs/html/lib/parser.dart
pkgs/html/lib/src/constants.dart
pkgs/html/lib/src/encoding_parser.dart
pkgs/html/lib/src/html_input_stream.dart
pkgs/html/lib/src/list_proxy.dart
pkgs/html/lib/src/query_selector.dart
pkgs/html/lib/src/token.dart
pkgs/html/lib/src/tokenizer.dart
pkgs/html/lib/src/treebuilder.dart
pkgs/html/lib/src/utils.dart
pkgs/html/test/dom_test.dart
pkgs/html/test/parser_feature_test.dart
pkgs/html/test/parser_test.dart
pkgs/html/test/query_selector_test.dart
pkgs/html/test/selectors/level1_baseline_test.dart
pkgs/html/test/selectors/level1_lib.dart
pkgs/html/test/selectors/selectors.dart
pkgs/html/test/support.dart
pkgs/html/test/tokenizer_test.dart
pkgs/html/test/trie_test.dart
pkgs/html/tool/generate_trie.dart
pkgs/pubspec_parse/test/git_uri_test.dart
pkgs/stack_trace/example/example.dart
pkgs/watcher/test/custom_watcher_factory_test.dart
pkgs/yaml_edit/example/example.dart

This check can be disabled by tagging the PR with skip-license-check.

[mosuem]

@sigurdm friendly ping!

[illaz]

@sigurdm Thank you for the suggestions. I amended the commit and also adapted the commit message. The branch name doesn't fit 100%, but if that matters, I could open a new PR.

[sigurdm]

The branch name has no effect. Don't mind that :)

[sigurdm]

I see there is a lint triggering. Could you fix that?

[illaz]

I see there is a lint triggering. Could you fix that?

Done :)

[illaz]

@sigurdm Hi, is there anything, I can do here besides rebasing from time to time? How and when is this change merged?

[sigurdm]

Sorry for the wait - I think this is good! Thanks for the patience.

Could you bump the patch version of pkg oauth, and add a note to the CHANGELOG?

[sigurdm]

Thanks for all the work and patience!

2.0.5 is now published!

[illaz]

Thanks for all the work and patience!

2.0.5 is now published!

Thank you, I'm proud to be part of this repo 😊