feat(agentrepo): report prose preflight argument blockers

internal/agentrepo/prose.go

@@ -33,6 +33,7 @@ func proseCommand(code *int) *cobra.Command {
 			*code = p.execute(args)
 		},
 	})
+	group.AddCommand(proseCommandPreflight(code))
 	return group
 }
 

internal/agentrepo/prose_preflight.go

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Tony Burns
+
+package agentrepo
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+func proseCommandPreflight(code *int) *cobra.Command {
+	return &cobra.Command{
+		Use:                "preflight TARGET [LINT COMMAND...]",
+		Short:              "Report whether a prose run can start",
+		DisableFlagParsing: true,
+		Run: func(cmd *cobra.Command, args []string) {
+			p := proseState{out: cmd.OutOrStdout(), stderr: cmd.ErrOrStderr(), run: diagnosisRunner(cmd.Context())}
+			*code = p.preflight(args)
+		},
+	}
+}
+
+// preflight reports the three argument-handling BLOCKED outcomes that precede any probe.
+func (p *proseState) preflight(args []string) int {
+	if p.checkout() != "" {
+		fmt.Fprintln(p.out, "verdict: BLOCKED (not a git repository)")
+		return 0
+	}
+	target := ""
+	if len(args) > 0 {
+		target = args[0]
+	}
+	fmt.Fprintf(p.out, "== fix-prose preflight ==\nroot:     %s\n", p.root)
+	if target == "" {
+		fmt.Fprintln(p.out, "target:   (none given)")
+		fmt.Fprintln(p.out, "verdict:  BLOCKED (no target in the arguments; ask which file)")
+		return 0
+	}
+	// The shell changes to the checkout root first. A relative target resolves there.
+	rel, _ := strings.CutPrefix(target, p.root+string(filepath.Separator))
+	if info, err := os.Stat(p.path(rel)); err != nil || !info.Mode().IsRegular() {
+		fmt.Fprintf(p.out, "target:   %s (missing)\n", rel)
+		fmt.Fprintln(p.out, "verdict:  BLOCKED (no such file)")
+		return 0
+	}
+	fmt.Fprintln(p.stderr, "preflight: scope probes are not ported yet")
+	const deferred = 2
+	return deferred
+}

internal/agentrepo/prose_preflight_test.go

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: Apache-2.0
+// Copyright Tony Burns
+
+package agentrepo_test
+
+import (
+	"bytes"
+	"errors"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/tbhb-dev/devtools/internal/agentrepo"
+)
+
+const proseBlockedHeader = "== fix-prose preflight ==\n"
+
+func proseGoPreflight(t *testing.T, dir string, args ...string) proseResult {
+	t.Helper()
+	t.Chdir(dir)
+	var out, stderr bytes.Buffer
+	code := agentrepo.Run(append([]string{"prose", "preflight"}, args...), nil, &out, &stderr)
+	return proseResult{code, out.String(), stderr.String()}
+}
+
+func proseShellPreflight(t *testing.T, dir string, args ...string) proseResult {
+	t.Helper()
+	_, source, _, ok := runtime.Caller(0)
+	require.True(t, ok)
+	script := filepath.Join(filepath.Dir(source), "../..",
+		"packages/agents/source/skills/fix-prose/shared/scripts/preflight.sh")
+	var out, stderr bytes.Buffer
+	c := exec.CommandContext(t.Context(), "bash")
+	c.Args = append(append(c.Args, script), args...)
+	c.Dir, c.Stdout, c.Stderr = dir, &out, &stderr
+	code := 0
+	if err := c.Run(); err != nil {
+		exit, isExit := errors.AsType[*exec.ExitError](err)
+		require.True(t, isExit, "%v", err)
+		code = exit.ExitCode()
+	}
+	return proseResult{code, out.String(), stderr.String()}
+}
+
+// proseOracle compares a Go report with the executed shell report where bash is available.
+func proseOracle(t *testing.T, root, dir string, got proseResult, args ...string) {
+	t.Helper()
+	if runtime.GOOS == "windows" {
+		return
+	}
+	want := proseShellPreflight(t, dir, args...)
+	require.Equal(t, want.Code, got.Code)
+	require.Equal(t, proseNormalize(root, want.Out), proseNormalize(root, got.Out))
+	require.Equal(t, proseNormalize(root, want.Err), proseNormalize(root, got.Err))
+}
+
+func TestProsePreflightOutsideRepository(t *testing.T) {
+	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
+	dir := t.TempDir()
+	// Stop Git's upward search at the temporary directory's parent, whatever TMPDIR holds.
+	t.Setenv("GIT_CEILING_DIRECTORIES", filepath.Dir(dir))
+	got := proseGoPreflight(t, dir, "DRAFT.md")
+	require.Equal(t, proseResult{0, "verdict: BLOCKED (not a git repository)\n", ""}, got)
+	proseOracle(t, dir, dir, got, "DRAFT.md")
+}
+
+func TestProsePreflightNoTarget(t *testing.T) {
+	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
+	f := newProseFixture(t, "bare")
+	got := proseGoPreflight(t, f.root)
+	want := proseBlockedHeader + "root:     " + f.root + "\n" +
+		"target:   (none given)\n" +
+		"verdict:  BLOCKED (no target in the arguments; ask which file)\n"
+	require.Equal(t, proseResult{0, want, ""}, got)
+	proseOracle(t, f.root, f.root, got)
+}
+
+func TestProsePreflightMissingTarget(t *testing.T) {
+	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
+	f := newProseFixture(t, "missing")
+	f.write(t, "sub/keep.md", "kept\n")
+	for name, c := range map[string]struct{ dir, target, shown string }{
+		"relative":          {f.root, "nope.md", "nope.md"},
+		"absolute":          {f.root, filepath.Join(f.root, "nope.md"), "nope.md"},
+		"relative to root":  {filepath.Join(f.root, "sub"), "keep.md", "keep.md"},
+		"absolute outside":  {f.root, filepath.Join(filepath.Dir(f.root), "nope.md"), filepath.Join(filepath.Dir(f.root), "nope.md")},
+		"directory":         {f.root, "sub", "sub"},
+		"extra lint config": {f.root, "nope.md", "nope.md"},
+	} {
+		t.Run(name, func(t *testing.T) {
+			t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
+			args := []string{c.target}
+			if name == "extra lint config" {
+				args = append(args, "vale", "--no-global")
+			}
+			got := proseGoPreflight(t, c.dir, args...)
+			want := proseBlockedHeader + "root:     " + f.root + "\n" +
+				"target:   " + c.shown + " (missing)\n" +
+				"verdict:  BLOCKED (no such file)\n"
+			require.Equal(t, proseResult{0, want, ""}, got)
+			proseOracle(t, f.root, c.dir, got, args...)
+		})
+	}
+}
+
+func TestProsePreflightExistingTargetIsNotPortedYet(t *testing.T) {
+	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
+	f := newProseFixture(t, "existing")
+	want := proseResult{
+		2,
+		proseBlockedHeader + "root:     " + f.root + "\n",
+		"preflight: scope probes are not ported yet\n",
+	}
+	require.Equal(t, want, proseGoPreflight(t, f.root, "DRAFT.md"))
+}