The Standard Library Was Already Enough: Rebuilding Taskfile in Pure Go

Description and use

A zero‑dependency task runner raptor built entirely with Go’s standard library, replacing go-task/task to achieve deterministic builds, reduced binary size, and simplified maintenance.

Problem

Replacing the popular Go task runner go-task/task with a zero‑dependency implementation to reduce audit surface and improve reproducibility.

Outcome

A fully functional, zero‑dependency task runner that matches go-task/task features, with reduced binary size, improved security, and deterministic incremental builds.

Workflow

• 1. Hand‑write an indentation‑sensitive YAML subset parser with line:column error reporting.
• 2. Implement a DAG scheduler using depth‑first search for topological sort and cycle detection.
• 3. Add bounded parallel execution via channel‑based semaphores scaling to runtime.NumCPU().
• 4. Enable incremental builds by tracking source and generate files with timestamps and crypto/sha256 content hashing.
• 5. Support dynamic variables and templating, evaluating { sh: cmd } once per run and providing template functions like {{.KEY | upper}} and for: loops.
• 6. Provide deterministic output modes: interleaved live streaming, prefixed lines, and topological group output.
• 7. Handle concurrency log tearing by spooling concurrent task streams to temporary files and re‑emitting them in DAG order when --ordered-output is enabled.
• 8. Replace each third‑party dependency with a standard library alternative (e.g., flag.FlagSet for Cobra, filepath.Match for globbing, os.CreateTemp for temp files).

Evidence

I replaced a Go tool that itself replaces make — and did it with an empty go.mod (zero third‑party imports).

Source

Within an hour, "writing a small YAML parser" turned into "writing a strict parser for a subset of YAML that fails loudly on invalid syntax."

Source