# version

Tells the editor what build of itself it is: a number, and — when the build recorded them — the commit it came from and when it was linked.

Imports two things from the standard library and nothing else. No tcell, no `ui`, no files read, no commands run, so asking costs nothing and can be done from anywhere.

## There is no version constant

There used to be, in `app`, and it was wrong for the fourteen commits after somebody last edited it. Nothing in committing, tagging or installing touches a Go constant, and an About box is exactly where a number nobody set gets believed.

So three sources are consulted in order, and the first that answers wins:

| Order | Source | Set by |
| --- | --- | --- |
| 1 | `stamp`, `commit`, `built` | `-ldflags -X`, from the Makefile and `scripts/install.sh` |
| 2 | `runtime/debug.ReadBuildInfo()` | The Go tool |
| 3 | `unknown` | Nothing |

`unknown` is deliberately **not** a number. The failure being designed against is a plausible-looking version nobody set, and a fallback of `0.1.0` would be exactly that.

## Two things the build system cannot do

**It does not read git tags.** A plain `go build .` can never report `0.1.0-14-g88a4c38`, however the code is written. It reports `devel` plus the commit, and the documentation says so rather than implying every build is equal. Anything that wants a tag has to be stamped, which is why the Makefile and the installer both do it.

**What it reports instead is a pseudo-version** — `v0.1.1-0.20260831165958-88a4c3859bf3` — which `isPseudoVersion` recognises and `fromBuildInfo` reports as `devel`. Shown as written it would claim a `0.1.1` patch release that does not exist. All three of the Go tool's forms end in the same 28-character tail; the character before the timestamp is a dash when no tag precedes the commit and a **dot** when one does, because the base then ends in `-0.` or `-pre.0.`. Getting that wrong is why the check has a test naming each form.

## `vcs.time` is not a build date

It is when the *commit* was made. Every binary is linked later than the commit it was built from, so labelling it "Built" would be false on all of them. A build date appears only when a build stamped one, which is the same rule the About box follows: a fact nobody recorded gets no line rather than an empty one.

## Why resolve is separate from Current

`Current` reads package-level variables the linker wrote and whatever the Go tool recorded — neither of which a test binary can be built into having. `resolve(stamp, commit, built, info)` takes all four as arguments, so every combination in the table above is an ordinary table-driven test with no build flags anywhere.

## Public API

| Name | What it does |
| --- | --- |
| `Info{Number, Commit, Built}` | What a binary knows about its own build; `Commit` and `Built` are empty when nothing recorded them |
| `Current() Info` | What *this* binary knows about itself |
| `(Info) String() string` | Every known part on one line, for `-version` |
| `(Info) BuiltAt() string` | `Built` rendered for a person: `2026-08-31 18:04 UTC` |

```go
info := version.Current()
fmt.Printf("%s %s\n", app.Name, info) // Turbo Go 0.2.0 (88a4c38, built …)

if info.Commit != "" {
    fmt.Println("Commit:", info.Commit)
}
```

Stamp it like this — the Makefile and `scripts/install.sh` both do:

```sh
go build -ldflags "-X 'rickub.com/turbo-editors/turbo-core/version.stamp=$(git describe --tags --dirty)'" .
```

## Anything that ships has to be stamped

Removing the constant moved a cost that used to be invisible: a build with no `-ldflags` used to carry the last number somebody typed, and now carries `devel`. That is better everywhere except in a **cross-compile**, where nothing else would have noticed — the host binary is stamped and correct while the five downloads say `devel`.

So `03-build-releases.sh` stamps every platform, taking the flags from `make ldflags` rather than repeating the `-X` paths, and runs the staged binary for its own machine before calling the release built. `release_test.go` holds that line.

## Tests

```sh
make test
go test ./version/
```