Add arg and flag completions

cmd/evaluate_all_command.go

@@ -12,6 +12,12 @@ func createEvaluateAllCommand() *cobra.Command {
 		Use:     "eval-all [expression] [yaml_file1]...",
 		Aliases: []string{"ea"},
 		Short:   "Loads _all_ yaml documents of _all_ yaml files and runs expression once",
+		ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+			if len(args) == 0 {
+				return nil, cobra.ShellCompDirectiveNoFileComp
+			}
+			return nil, cobra.ShellCompDirectiveDefault
+		},
 		Example: `
 # Merge f2.yml into f1.yml (in place)
 yq eval-all --inplace 'select(fileIndex == 0) * select(fileIndex == 1)' f1.yml f2.yml