fix: show usage help when long_about is defined w/o args/flags

[nkakouros]

Description:

Summary

• When a task script defines #USAGE long_about (or other metadata-only directives like before_help, after_help, examples) but no arg or flag, mise run task --help now correctly renders usage-based help instead of the generic "This task does not accept any arguments" message.
• Adds a new has_any_usage_spec() function that checks for any meaningful usage spec content (not just args/flags/subcommands), used only for the help display decision. The existing has_any_args_defined() remains unchanged for runtime argument parsing.

Steps to reproduce

mkdir -p .mise/tasks
cat <<'EOF' > .mise/tasks/example
#!/usr/bin/env bash
#USAGE long_about """
#USAGE Detailed description here.
#USAGE """
echo "hello"
EOF
chmod +x .mise/tasks/example
                                                                                                                                                                                                                                                                   
mise run example --help
# Before: shows generic "This task does not accept any arguments"
# After: shows "Detailed description here."                                                                                                                                                                                                                       

Test plan

• Added e2e test for long_about without args/flags (test_task_args_position test 9)
• All existing e2e tests for test_task_args_position pass
• All 546 unit tests pass

[gemini-code-assist]

Code Review

This pull request enhances the task help system by introducing the has_any_usage_spec function, which ensures that usage-based help is displayed if any usage metadata (such as long_about) is present, even if no arguments or flags are defined. A new end-to-end test was added to verify this behavior. The reviewer identified that spec.about and spec.cmd.help_md were missing from the new check and provided a code suggestion to include them for more comprehensive coverage.

[greptile-apps]

Greptile Summary

This PR fixes a display bug where mise run <task> --help showed the generic "This task does not accept any arguments" message when a task script defined only metadata-only USAGE directives (e.g. long_about, before_help, after_help, examples) without any formal args or flags.

Key changes:

• Introduces has_any_usage_spec() in task_script_parser.rs that broadens the help-routing decision beyond args/flags/subcommands to include metadata fields (about, about_long, about_md, help_long, help_md, before_help, after_help, after_help_long, examples).
• before_help_long is deliberately excluded from the check because populate_spec_metadata() auto-sets it for any task with depends entries — this addresses the previously reported false-positive regression.
• src/cli/run.rs is updated to call the new guard, and the old has_any_args_defined remains unchanged for runtime argument parsing.
• An e2e test (Test 9 in test_task_args_position) validates the fix end-to-end.

Confidence Score: 5/5

• Safe to merge — targeted fix with no regressions; the prior before_help_long false-positive is correctly excluded.
• All changed fields in has_any_usage_spec are only populated by explicit user-defined USAGE directives, not by populate_spec_metadata auto-filling. The one auto-set field (before_help_long) is explicitly excluded with a doc comment. The fix is minimal, well-scoped, and backed by both an e2e test and all 546 passing unit tests.
• No files require special attention.

Important Files Changed

Filename	Overview
src/task/task_script_parser.rs	Adds has_any_usage_spec() that checks for meaningful usage content (about, about_long, help_long, before_help, after_help, examples) on top of has_any_args_defined(); correctly excludes before_help_long which is auto-set by populate_spec_metadata for dependency tasks.
src/cli/run.rs	Swaps the help-display guard from has_any_args_defined to has_any_usage_spec, enabling metadata-only specs (e.g. long_about without args) to trigger usage-based rendering.
src/task/mod.rs	Re-exports the new has_any_usage_spec function alongside the existing has_any_args_defined; no logic changes here.
e2e/tasks/test_task_args_position	Adds Test 9 covering the long_about-only case, creating a temporary task file and asserting the help output contains the description text.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A["mise run <task> --help"] --> B["parse_usage_spec_for_display()"]
    B --> C["populate_spec_metadata()"]
    C --> D{"has_any_usage_spec(spec)?"}
    D -->|"args / flags / subcommands\nOR about / about_long / about_md\nOR help_long / help_md\nOR before_help / after_help / after_help_long\nOR examples"| E["render_help() — usage-based help"]
    D -->|"None of the above\n(note: before_help_long is\nauto-set for depends, so excluded)"| F["display_task_help() — generic fallback"]

Loading

_{Reviews (4): Last reviewed commit: "fix(task): include before_help in has_an..." | Re-trigger Greptile}