c/snap, t/main/snap-tasks: fix spread test, add formatMixin

Author: Rnfudge02

cmd/snap/cmd_changes.go

@@ -20,7 +20,6 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"regexp"
 	"sort"
@@ -51,17 +50,15 @@ type cmdChanges struct {
 type cmdTasks struct {
 	timeMixin
 	changeIDMixin
-	Format string `long:"format" required:"false"`
+	formatMixin
 }
 
 func init() {
 	addCommand("changes", shortChangesHelp, longChangesHelp,
 		func() flags.Commander { return &cmdChanges{} }, timeDescs, nil)
 	addCommand("tasks", shortTasksHelp, longTasksHelp,
 		func() flags.Commander { return &cmdTasks{} },
-		changeIDMixinOptDesc.also(timeDescs).also(map[string]string{
-			"format": i18n.G("Output format (supported: json)."),
-		}),
+		changeIDMixinOptDesc.also(timeDescs).also(formatArgsHelp),
 		changeIDMixinArgDesc).alias = "change"
 }
 
@@ -163,15 +160,9 @@ func (c *cmdTasks) showChange(chid string) error {
 		return err
 	}
 
-	if c.Format == "json" {
-		data, err := json.Marshal(chg)
-		if err != nil {
-			return err
-		}
-		fmt.Fprint(Stdout, string(data))
-		return nil
-	} else if c.Format != "" {
-		return fmt.Errorf(i18n.G("unsupported format: %s"), c.Format)
+	if c.Format != "text" && c.Format != "" {
+		err = c.formatNonText(chg)
+		return err
 	}
 
 	w := tabWriter()

cmd/snap/cmd_changes_test.go

@@ -257,8 +257,12 @@ func (s *SnapSuite) TestTasksJSON(c *check.C) {
 	c.Check(chg.Tasks[0].Summary, check.Equals, "some summary")
 	c.Check(chg.Tasks[0].Status, check.Equals, "Do")
 
+	// If format (which has defined values) gets passed an invalid value, the parser wraps it in `'.
+	_, err = snap.Parser(snap.Client()).ParseArgs([]string{"tasks", "--format=", "42"})
+	c.Assert(err, check.ErrorMatches, ".*Invalid value `' for option `--format'. Allowed values are: .* or json")
 	_, err = snap.Parser(snap.Client()).ParseArgs([]string{"tasks", "--format=random", "42"})
-	c.Assert(err, check.ErrorMatches, ".*unsupported format: random")
+	c.Assert(err, check.ErrorMatches, ".*Invalid value `random' for option `--format'. Allowed values are: .* or json")
+
 }
 
 func (s *SnapSuite) TestNoChanges(c *check.C) {

cmd/snap/main.go

@@ -20,6 +20,7 @@
 package main
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -215,6 +216,28 @@ func (ch *clientMixin) setClient(cli *client.Client) {
 	ch.client = cli
 }
 
+type formatMixin struct {
+	//lint:ignore SA5008 "choice" tag is intentionally duplicated
+	Format string `long:"format" default:"text" choice:"text" choice:"json"`
+}
+
+var formatArgsHelp = map[string]string{
+	"format": i18n.G("Output format"),
+}
+
+func (mx formatMixin) formatNonText(result any) error {
+	switch mx.Format {
+	case "json":
+		data, err := json.Marshal(result)
+		if err != nil {
+			return err
+		}
+		fmt.Fprintln(Stdout, string(data))
+		return nil
+	}
+	panic(fmt.Sprintf("internal error: invalid format option %q", mx.Format))
+}
+
 func firstNonOptionIsRun() bool {
 	if len(os.Args) < 2 {
 		return false

tests/main/snap-tasks/tasks.yaml

@@ -4,20 +4,13 @@ details: |
     Verifies that the command 'snap tasks' properly lists the tasks
     associated with a change. Also check the error scenarios.
 
-prepare: |
-    # Install local test snap
-    "$TESTSTOOLS"/install-local test-snap-with-components
-
-restore: |
-    snap remove --purge test-snap-tasks || true
-
 execute: |
-    echo "Install component to trigger a change"
-    snap install test-snap-with-components+comp1
+    echo "Install snap to trigger a change"
+    "$TESTSTOOLS"/install-local test-snap-with-components
 
     echo "Get the change ID for the install operation"
-    CHANGE_ID_1=$(snap changes | grep "Install snap \"test-snap-with-components\"" | awk '{print $1}')
+    CHANGE_ID=$(snap changes | grep "Install \"test-snap-with-components\" snap" | awk '{print $1}')
 
     # Check that valid JSON output is produced for the change, and that it contains the expected task with the expected state.
     echo "Check that 'snap tasks' lists the task for the change (and accepts the --format option)"
-    snap tasks --format json "$CHANGE_ID_1" | jq -e '.tasks | any(.id == "remove+comp1" and (.status == "Done" or .status == "done" or .state == "done"))' > /dev/null
+    snap tasks --format json "$CHANGE_ID" | jq -e '.tasks | any(.id == "$CHANGE_ID" and (.status == "Done" or .status == "done" or .state == "done"))' > /dev/null