Add 'ask edit' subcommand and collapse multi-line task descriptions

- ask edit opens $EDITOR and creates a task from the (multi-line) content,
  reusing the shared internal/editor package
- collapse newlines in list output and fish completion so multi-line
  descriptions render on one line and don't break completion

Bump version to 0.40.0

Amp-Thread-ID: https://ampcode.com/threads/T-019e96a1-9c8e-73d6-95b4-b55cb12cc762
Co-authored-by: Amp <amp@ampcode.com>

9 files changed, 184 insertions, 7 deletions

diff --git a/internal/askcli/command_add.go b/internal/askcli/command_add.go
index 096046d..ccfb034 100644
--- a/internal/askcli/command_add.go
+++ b/internal/askcli/command_add.go
@@ -27,6 +27,12 @@ func (d *Dispatcher) handleAdd(ctx context.Context, args []string, stdout, stder
 		writeInfoError(stderr, err)
 		return code, nil
 	}
+	return d.createTask(ctx, modifiers, description, dependencyUUIDs, stdout, stderr)
+}
+
+// createTask creates a Taskwarrior task from the given modifiers, description,
+// and resolved dependency UUIDs, assigns an alias, and prints the created task.
+func (d *Dispatcher) createTask(ctx context.Context, modifiers []string, description string, dependencyUUIDs []string, stdout, stderr io.Writer) (int, error) {
 	var outBuf bytes.Buffer
 	// rc.verbose=nothing keeps Taskwarrior quiet by default. rc.verbose=new-uuid
 	// then re-enables the UUID-only confirmation we parse below.
@@ -36,7 +42,7 @@ func (d *Dispatcher) handleAdd(ctx context.Context, args []string, stdout, stder
 		taskArgs = append(taskArgs, "depends:"+strings.Join(dependencyUUIDs, ","))
 	}
 	taskArgs = append(taskArgs, description)
-	code, err = d.runner.Run(ctx, taskArgs, nil, &outBuf, stderr)
+	code, err := d.runner.Run(ctx, taskArgs, nil, &outBuf, stderr)
 	if code != 0 {
 		return code, err
 	}
diff --git a/internal/askcli/command_complete_uuids.go b/internal/askcli/command_complete_uuids.go
index bc160b6..5c26649 100644
--- a/internal/askcli/command_complete_uuids.go
+++ b/internal/askcli/command_complete_uuids.go
@@ -85,9 +85,11 @@ func taskCompletionAliasItems(tasks []TaskExport, aliases map[string]string) []s
 	return items
 }
 
-// truncateDescription shortens s to at most maxLen characters, appending "…"
-// when the string is cut, so the completion hint fits on one line.
+// truncateDescription collapses any embedded newlines to keep the completion
+// item on a single line, then shortens s to at most maxLen characters,
+// appending "…" when the string is cut, so the completion hint fits on one line.
 func truncateDescription(s string, maxLen int) string {
+	s = oneLineDescription(s)
 	runes := []rune(s)
 	if len(runes) <= maxLen {
 		return s
diff --git a/internal/askcli/command_complete_uuids_test.go b/internal/askcli/command_complete_uuids_test.go
index 0859acc..2c1b5fd 100644
--- a/internal/askcli/command_complete_uuids_test.go
+++ b/internal/askcli/command_complete_uuids_test.go
@@ -255,3 +255,31 @@ func TestTruncateDescription_Unicode(t *testing.T) {
 		t.Fatalf("truncateDescription = %q, want %q", got, "日本語…")
 	}
 }
+
+func TestTruncateDescription_CollapsesNewlines(t *testing.T) {
+	// Multi-line descriptions must collapse to a single line so the
+	// tab-separated completion output is not broken into bogus entries.
+	got := truncateDescription("first line\nsecond line\n\nfourth", 100)
+	if got != "first line second line fourth" {
+		t.Fatalf("truncateDescription = %q, want single-line collapse", got)
+	}
+	if strings.ContainsAny(got, "\r\n") {
+		t.Fatalf("truncateDescription left a newline in %q", got)
+	}
+}
+
+func TestOneLineDescription(t *testing.T) {
+	cases := map[string]string{
+		"plain":                   "plain",
+		"a\nb":                    "a b",
+		"a\r\nb":                  "a b",
+		"a\n\n\nb":                "a b",
+		"  leading\n  indented  ": "leading indented",
+		"keep  internal  spaces":  "keep  internal  spaces",
+	}
+	for in, want := range cases {
+		if got := oneLineDescription(in); got != want {
+			t.Fatalf("oneLineDescription(%q) = %q, want %q", in, got, want)
+		}
+	}
+}
diff --git a/internal/askcli/command_edit.go b/internal/askcli/command_edit.go
new file mode 100644
index 0000000..585f550
--- /dev/null
+++ b/internal/askcli/command_edit.go
@@ -0,0 +1,30 @@
+package askcli
+
+import (
+	"context"
+	"io"
+
+	"codeberg.org/snonux/hexai/internal/editor"
+)
+
+// captureFromEditor opens the user's editor on a temporary file and returns its
+// trimmed contents after the editor exits. It is a variable so tests can stub it.
+var captureFromEditor = func() (string, error) {
+	return editor.OpenTempAndEdit(nil)
+}
+
+// handleEdit opens the configured editor on a temporary file and creates a new
+// task from the resulting (possibly multi-line) content.
+func (d *Dispatcher) handleEdit(ctx context.Context, args []string, stdout, stderr io.Writer) (int, error) {
+	_ = args
+	description, err := captureFromEditor()
+	if err != nil {
+		writeInfoError(stderr, err)
+		return 1, nil
+	}
+	if description == "" {
+		_, _ = io.WriteString(stderr, "error: ask edit aborted: empty description\n")
+		return 1, nil
+	}
+	return d.createTask(ctx, nil, description, nil, stdout, stderr)
+}
diff --git a/internal/askcli/command_edit_test.go b/internal/askcli/command_edit_test.go
new file mode 100644
index 0000000..3f4b778
--- /dev/null
+++ b/internal/askcli/command_edit_test.go
@@ -0,0 +1,86 @@
+package askcli
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"strings"
+	"testing"
+)
+
+func stubEditorCapture(t *testing.T, content string, err error) {
+	t.Helper()
+	old := captureFromEditor
+	captureFromEditor = func() (string, error) {
+		return content, err
+	}
+	t.Cleanup(func() { captureFromEditor = old })
+}
+
+func TestHandleEdit_Success(t *testing.T) {
+	now := useIsolatedTaskAliasCache(t)
+	writeTaskAliasCacheForTest(t, taskAliasCache{
+		NextID: 1,
+		Entries: []taskAliasCacheEntry{
+			{UUID: "existing-uuid", Alias: "0", CreatedAt: now},
+		},
+	})
+	// editor.OpenTempAndEdit trims content, so mimic that here.
+	stubEditorCapture(t, "Multi line\ntask description", nil)
+
+	var capturedArgs []string
+	d := NewDispatcher(&spyRunner{runFn: func(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) (int, error) {
+		capturedArgs = args
+		_, _ = io.WriteString(stdout, "Created task abc-123-def.")
+		return 0, nil
+	}})
+
+	var stdout, stderr bytes.Buffer
+	code, _ := d.Dispatch(context.Background(), []string{"edit"}, nil, &stdout, &stderr)
+	if code != 0 {
+		t.Fatalf("edit code = %d stderr = %q", code, stderr.String())
+	}
+	if got := strings.TrimSpace(stdout.String()); got != "created task 1" {
+		t.Fatalf("stdout = %q, want created task 1", stdout.String())
+	}
+	if len(capturedArgs) == 0 || capturedArgs[len(capturedArgs)-1] != "Multi line\ntask description" {
+		t.Fatalf("description arg = %v, want trimmed multi-line content", capturedArgs)
+	}
+}
+
+func TestHandleEdit_EmptyContentAborts(t *testing.T) {
+	stubEditorCapture(t, "", nil)
+
+	d := NewDispatcher(&spyRunner{runFn: func(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) (int, error) {
+		t.Fatalf("runner should not be called on empty content")
+		return 0, nil
+	}})
+
+	var stdout, stderr bytes.Buffer
+	code, _ := d.Dispatch(context.Background(), []string{"edit"}, nil, &stdout, &stderr)
+	if code != 1 {
+		t.Fatalf("edit code = %d, want 1", code)
+	}
+	if !strings.Contains(stderr.String(), "empty description") {
+		t.Fatalf("stderr = %q, want empty description error", stderr.String())
+	}
+}
+
+func TestHandleEdit_EditorError(t *testing.T) {
+	stubEditorCapture(t, "", errors.New("boom"))
+
+	d := NewDispatcher(&spyRunner{runFn: func(ctx context.Context, args []string, stdin io.Reader, stdout, stderr io.Writer) (int, error) {
+		t.Fatalf("runner should not be called when editor fails")
+		return 0, nil
+	}})
+
+	var stdout, stderr bytes.Buffer
+	code, _ := d.Dispatch(context.Background(), []string{"edit"}, nil, &stdout, &stderr)
+	if code != 1 {
+		t.Fatalf("edit code = %d, want 1", code)
+	}
+	if !strings.Contains(stderr.String(), "boom") {
+		t.Fatalf("stderr = %q, want editor error", stderr.String())
+	}
+}
diff --git a/internal/askcli/commands_registry.go b/internal/askcli/commands_registry.go
index c755560..31773d5 100644
--- a/internal/askcli/commands_registry.go
+++ b/internal/askcli/commands_registry.go
@@ -207,6 +207,12 @@ func init() {
 		includeInCompletion: true,
 	})
 	commandRegistry.add(commandEntry{
+		name:                "edit",
+		description:         "Create a task from $EDITOR content",
+		handler:             wrapSimpleCommand((*Dispatcher).handleEdit),
+		includeInCompletion: true,
+	})
+	commandRegistry.add(commandEntry{
 		name:                "fish",
 		description:         "Emit Fish shell completion script",
 		handler:             wrapSimpleCommand((*Dispatcher).handleFish),
diff --git a/internal/askcli/dispatch.go b/internal/askcli/dispatch.go
index 81b8944..924ca67 100644
--- a/internal/askcli/dispatch.go
+++ b/internal/askcli/dispatch.go
@@ -80,6 +80,7 @@ func (d *Dispatcher) help(w io.Writer) (int, error) {
 	_, _ = io.WriteString(w, "  ask no-agent <subcommand...>   Alias for ask na\n")
 	_, _ = io.WriteString(w, "\nSubcommands:\n")
 	_, _ = io.WriteString(w, "  ask add [mods...] [depends:<id|uuid>,...] <description...> Create a new task and print created task <id>\n")
+	_, _ = io.WriteString(w, "  ask edit                     Open $EDITOR and create a task from its content\n")
 	_, _ = io.WriteString(w, "  ask list [filters]           List active tasks (default)\n")
 	_, _ = io.WriteString(w, "  ask ready                   List READY tasks (not blocked)\n")
 	_, _ = io.WriteString(w, "  ask completed               List completed tasks\n")
diff --git a/internal/askcli/formatter.go b/internal/askcli/formatter.go
index 8d62125..93b8921 100644
--- a/internal/askcli/formatter.go
+++ b/internal/askcli/formatter.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"regexp"
 	"slices"
 	"strings"
 
@@ -55,14 +56,15 @@ func taskListWidthsFor(tasks []TaskExport, aliases map[string]string, terminalWi
 		widths.Status = max(widths.Status, len(t.Status))
 		widths.Started = max(widths.Started, len(formatTaskStarted(t)))
 		widths.Tags = max(widths.Tags, len(formatTaskTags(t.Tags)))
-		longestDescription = max(longestDescription, len(t.Description))
+		longestDescription = max(longestDescription, len(oneLineDescription(t.Description)))
 	}
 	widths.Description = taskListDescriptionWidth(widths, terminalWidth, longestDescription)
 	return widths
 }
 
 func writeTaskListHeader(b *strings.Builder, widths taskListWidths) {
-	fmt.Fprintf(b, "%-*s | %-*s | %-*s | %-*s | %-*s | %-*s | %-*s\n",
+	fmt.Fprintf(
+		b, "%-*s | %-*s | %-*s | %-*s | %-*s | %-*s | %-*s\n",
 		widths.Urgency, "Urg",
 		widths.Priority, "Pri",
 		widths.ID, "ID",
@@ -79,7 +81,8 @@ func writeTaskListSeparator(b *strings.Builder, widths taskListWidths) {
 }
 
 func writeTaskListRow(b *strings.Builder, widths taskListWidths, t TaskExport, aliases map[string]string) {
-	fmt.Fprintf(b, "%-*s | %-*s | %-*s | %-*s | %-*s | %-*s | %-*s\n",
+	fmt.Fprintf(
+		b, "%-*s | %-*s | %-*s | %-*s | %-*s | %-*s | %-*s\n",
 		widths.Urgency, fmt.Sprintf("%.1f", t.Urgency),
 		widths.Priority, t.Priority,
 		widths.ID, displayTaskAlias(t.UUID, aliases),
@@ -98,6 +101,7 @@ func formatTaskTags(tags []string) string {
 }
 
 func formatTaskDescription(desc string, width int) string {
+	desc = oneLineDescription(desc)
 	if width <= 0 || len(desc) <= width {
 		return desc
 	}
@@ -107,6 +111,20 @@ func formatTaskDescription(desc string, width int) string {
 	return desc[:width-3] + "..."
 }
 
+// newlineRun matches a run of one or more line breaks together with any inline
+// whitespace surrounding them.
+var newlineRun = regexp.MustCompile(`[ \t]*[\r\n]+[ \t]*`)
+
+// oneLineDescription collapses any embedded line breaks in a task description
+// into a single space so multi-line descriptions render on one line and never
+// break the tab-separated completion output or the task list table.
+func oneLineDescription(desc string) string {
+	if !strings.ContainsAny(desc, "\r\n") {
+		return desc
+	}
+	return strings.TrimSpace(newlineRun.ReplaceAllString(desc, " "))
+}
+
 func formatTaskStarted(t TaskExport) string {
 	if t.Start == "" {
 		return "no"
diff --git a/internal/version.go b/internal/version.go
index ba6df42..f99e47f 100644
--- a/internal/version.go
+++ b/internal/version.go
@@ -1,4 +1,4 @@
 // Package internal provides the Hexai semantic version identifier used by CLI and LSP binaries.
 package internal
 
-const Version = "0.39.5"
+const Version = "0.40.0"