fix: shell autocomplete bypasses preprocessing and completes attribute values

Bypass Execute() preprocessing for __complete/__completeNoDesc so Cobra's
built-in completion handles shell TAB without creating tasks. Add root
ValidArgsFunction for flexible syntax (e.g. "opal 1 de<TAB>" → delete),
attribute value completions (status:pending, priority:H, date synonyms),
and NoSpace directive on key: completions to avoid trailing space.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

opal-task/cmd/completions.go

@@ -2,14 +2,37 @@ package cmd
 
 import (
 	"fmt"
+	"strings"
 
 	"git.jnss.me/joakim/opal/internal/engine"
 	"github.com/spf13/cobra"
 )
 
 // taskFilterCompletion provides dynamic completions for task filter arguments.
-// Suggests +tag and project:name completions from the database.
+// Suggests +tag, project:name, and attribute value completions from the database.
 func taskFilterCompletion(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	// If typing a key:value, complete the value part
+	if idx := strings.IndexByte(toComplete, ':'); idx >= 0 {
+		key := toComplete[:idx]
+		if engine.ValidAttributeKeys[key] {
+			return attributeValueCompletions(key, toComplete), cobra.ShellCompDirectiveNoFileComp
+		}
+	}
+
+	// If toComplete is a prefix of an attribute key, return only key:
+	// completions with NoSpace so the cursor stays after the colon.
+	if toComplete != "" && !strings.HasPrefix(toComplete, "+") && !strings.HasPrefix(toComplete, "-") {
+		var keyCompletions []string
+		for key := range engine.ValidAttributeKeys {
+			if strings.HasPrefix(key, toComplete) {
+				keyCompletions = append(keyCompletions, fmt.Sprintf("%s:", key))
+			}
+		}
+		if len(keyCompletions) > 0 {
+			return keyCompletions, cobra.ShellCompDirectiveNoFileComp | cobra.ShellCompDirectiveNoSpace
+		}
+	}
+
 	var completions []string
 
 	tags, err := engine.GetAllTags()
@@ -31,10 +54,69 @@ func taskFilterCompletion(cmd *cobra.Command, args []string, toComplete string)
 		completions = append(completions, fmt.Sprintf("%s:", key))
 	}
 
-	return completions, cobra.ShellCompDirectiveNoFileComp
+	return completions, cobra.ShellCompDirectiveNoFileComp | cobra.ShellCompDirectiveNoSpace
+}
+
+// attributeValueCompletions returns key:value completions for a known attribute key.
+// Cobra filters by prefix automatically, so we return all values prefixed with "key:".
+func attributeValueCompletions(key, toComplete string) []string {
+	var values []string
+
+	switch key {
+	case "status":
+		values = []string{"pending", "completed", "deleted", "recurring"}
+	case "priority":
+		values = []string{"H", "M", "L"}
+	case "project":
+		projects, err := engine.GetAllProjects()
+		if err == nil {
+			values = projects
+		}
+	case "due", "wait", "scheduled", "until":
+		values = []string{
+			"today", "tomorrow", "yesterday", "now",
+			"eod", "sow", "eow", "som", "eom",
+			"mon", "tue", "wed", "thu", "fri", "sat", "sun",
+		}
+	case "recur":
+		values = []string{"daily", "weekly", "monthly", "yearly", "1d", "1w", "2w", "1m", "1y"}
+	}
+
+	completions := make([]string, 0, len(values))
+	for _, v := range values {
+		completions = append(completions, fmt.Sprintf("%s:%s", key, v))
+	}
+	return completions
+}
+
+// rootValidArgsFunction provides completions for root-level arguments,
+// enabling flexible syntax like "opal 1 de<TAB>" to complete to "delete".
+func rootValidArgsFunction(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	// Delegate to taskFilterCompletion first — if toComplete is a partial
+	// attribute key, it returns early with NoSpace and we should honour that.
+	filterCompletions, directive := taskFilterCompletion(cmd, args, toComplete)
+
+	var completions []string
+
+	// Suggest command names
+	for _, name := range commandNames {
+		completions = append(completions, name)
+	}
+
+	// Suggest report names
+	for _, name := range reportNames {
+		completions = append(completions, name)
+	}
+
+	completions = append(completions, filterCompletions...)
+
+	return completions, directive
 }
 
 func init() {
+	// Root command completions for flexible syntax (e.g., "opal 1 de<TAB>")
+	rootCmd.ValidArgsFunction = rootValidArgsFunction
+
 	// Register dynamic completions for commands that accept filters
 	addCmd.ValidArgsFunction = taskFilterCompletion
 	doneCmd.ValidArgsFunction = taskFilterCompletion

opal-task/cmd/root.go

@@ -56,6 +56,7 @@ var rootCmd = &cobra.Command{
 	Short: "Opal task manager - taskwarrior-inspired CLI task management",
 	Long: `Opal is a powerful command-line task manager.
 It supports filtering, tags, priorities, projects, and recurring tasks.`,
+	Args: cobra.ArbitraryArgs,
 	Run: func(cmd *cobra.Command, args []string) {
 		// Default behavior: run configured default report (defaults to "list")
 		parsed := getParsedArgs(cmd)
@@ -87,6 +88,11 @@ func Execute() error {
 		if firstArg == "-h" || firstArg == "--help" || firstArg == "help" {
 			return rootCmd.Execute()
 		}
+		// Let Cobra's built-in completion machinery handle shell completions
+		// directly, bypassing preprocessing that would create tasks.
+		if firstArg == "__complete" || firstArg == "__completeNoDesc" {
+			return rootCmd.Execute()
+		}
 	}
 
 	// Preprocess arguments (read-only scan — os.Args is never mutated)