fix(install): use version_expr for Flutter to fix version resolution

[jdx]

Summary

• Flutter's Google API returns releases in newest-first order, which causes mise install flutter to resolve to an old version (3.22.1) instead of the latest (3.38.x)
• Switch from version_json_path to version_expr with sortVersions() to ensure proper ascending semver order
• Adds a unit test for the Flutter version_expr parsing

Fixes #7863 (comment)

Also submitted jdx/expr.rs#23 to fix braceless predicate parsing in expr.rs (Go expr-lang compatibility), which is why this PR uses {#.channel == "stable"} with braces.

Test plan

• Unit test test_parse_flutter_with_version_expr verifies correct filtering and sorting
• All existing tests pass
• Linting passes

🤖 Generated with Claude Code

---

Note

Low Risk
Low risk: registry config change and a new unit test; behavior change is limited to how Flutter versions are extracted/sorted from the upstream JSON.

Overview
Fixes Flutter version resolution by switching the registry backend from version_json_path to a version_expr that filters stable releases and applies sortVersions() so installs pick the latest stable version.

Adds a unit test (test_parse_flutter_with_version_expr) to validate the expr-based filtering/sorting behavior against Flutter-style JSON.

^{Written by Cursor Bugbot for commit 9af283d. This will update automatically on new commits. Configure here.}

[gemini-code-assist]

Summary of Changes

Hello @jdx, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request resolves an issue with Flutter version resolution in mise by switching to version_expr and adding a unit test to ensure correct version ordering. This change ensures that the latest stable version of Flutter is installed.

Highlights

• Version Resolution: Addresses an issue where mise install flutter was resolving to an older version of Flutter due to the order of releases returned by Google's API.
• Version Expression: Switched from version_json_path to version_expr using sortVersions() to ensure proper ascending semver order for Flutter versions.
• Unit Test: Added a unit test (test_parse_flutter_with_version_expr) to verify the correct filtering and sorting of Flutter versions.

Changelog

• registry/flutter.toml
  • Switched from version_json_path to version_expr to ensure proper semver sorting of Flutter versions.
• src/backend/version_list.rs
  • Added a unit test to verify correct parsing of Flutter versions using version_expr.

Activity

• The PR addresses issue Issues with Flutter installation: Malformed URL and incorrect version sorting #7863 (comment).
• A related pull request (fix: support braceless predicates matching Go expr-lang behavior expr.rs#23) was submitted to fix braceless predicate parsing in expr.rs.

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[Copilot]

Pull request overview

Updates Flutter’s version resolution to correctly select the latest stable release by using an expression-based extractor that filters + semver-sorts versions.

Changes:

• Switch Flutter registry entry from version_json_path to version_expr using sortVersions().
• Add a unit test validating version_expr filtering (stable-only) and ascending semver ordering.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/backend/version_list.rs	Adds a regression/unit test to ensure version_expr correctly filters and sorts Flutter releases.
registry/flutter.toml	Updates Flutter backend config to use version_expr with filtering + semver sorting so “latest” resolves correctly.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

The version_expr is non-trivial and encodes an important behavioral assumption (stable-only filtering + ascending semver order so resolution picks the latest). Consider adding a brief comment above version_expr explaining (1) why sorting is necessary for Flutter’s newest-first API response and (2) why the predicate uses braces for expr-lang compatibility, so future maintainers don’t ‘simplify’ it back and reintroduce the bug.

Suggested change

	[backends.options]
	[backends.options]
	# Note: Flutter's releases API returns newest-first; we filter to "stable" and then sort
	# versions in ascending semver so resolution sees the latest correctly. The { ... } lambdas
	# are required for expr-lang compatibility; do not simplify this predicate shape.

[Copilot]

This test embeds the same version_expr string that is now also in registry/flutter.toml. To reduce the risk of them drifting out of sync, consider defining a local const FLUTTER_VERSION_EXPR: &str = ...; in the test module (or otherwise centralizing it for tests) and referencing that constant here.

[gemini-code-assist]

Code Review

This pull request fixes an issue with Flutter version resolution by switching from version_json_path to version_expr. This allows for proper sorting of versions, as the Flutter API returns them in newest-first order. The change is accompanied by a new unit test that validates the filtering and sorting logic. The changes look good and effectively address the problem. I have one minor suggestion to improve the readability of the new test case.

[gemini-code-assist]

To improve readability, consider extracting the complex version_expr string into a constant. This makes the parse_version_list call cleaner and the expression easier to manage.

Suggested change

	fn test_parse_flutter_with_version_expr() {
	let content = r#"{
	"releases": [
	{"version": "3.38.7", "channel": "stable"},
	{"version": "3.41.0-0.0.pre", "channel": "beta"},
	{"version": "3.38.6", "channel": "stable"},
	{"version": "1.0.0", "channel": "stable"}
	]
	}"#;
	let versions = parse_version_list(
	content,
	None,
	None,
	Some(r#"fromJSON(body).releases | filter({#.channel == "stable"}) | map({#.version}) | sortVersions()"#),
	)
	fn test_parse_flutter_with_version_expr() {
	const FLUTTER_VERSION_EXPR: &str = r#"sortVersions(map(filter(fromJSON(body).releases, {#.channel == "stable"}), {#.version}))"#;
	let content = r#"{
	"releases": [
	{"version": "3.38.7", "channel": "stable"},
	{"version": "3.41.0-0.0.pre", "channel": "beta"},
	{"version": "3.38.6", "channel": "stable"},
	{"version": "1.0.0", "channel": "stable"}
	]
	}"#;
	let versions = parse_version_list(
	content,
	None,
	None,
	Some(FLUTTER_VERSION_EXPR),
	)

[github-actions]

Hyperfine Performance

mise x -- echo

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2026.2.8 x -- echo	21.4 ± 0.3	20.8	22.7	1.00
mise x -- echo	21.5 ± 0.6	20.9	28.3	1.01 ± 0.03

mise env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2026.2.8 env	20.8 ± 0.2	20.4	22.1	1.00
mise env	21.1 ± 0.4	20.4	22.4	1.01 ± 0.02

mise hook-env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2026.2.8 hook-env	21.5 ± 0.3	20.9	23.4	1.00
mise hook-env	21.7 ± 0.4	21.1	25.8	1.01 ± 0.03

mise ls

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2026.2.8 ls	19.8 ± 0.3	19.3	21.2	1.00
mise ls	19.8 ± 0.3	19.3	21.2	1.00 ± 0.02

xtasks/test/perf

Command	mise-2026.2.8	mise	Variance
install (cached)	117ms	117ms	+0%
ls (cached)	73ms	74ms	-1%
bin-paths (cached)	76ms	76ms	+0%
task-ls (cached)	532ms	536ms	+0%