cmd/tier: add -cancel flag to subscribe command (#209)

This adds support for canceling a subscription for an org via the
subscribe sub-command.

cmd/tier/cline/cline.go

@@ -116,7 +116,7 @@ func (d *Data) RunFail(args ...string) {
 func (d *Data) Run(args ...string) {
 	d.t.Helper()
 	if err := d.doRun(args...); err != nil {
-		d.t.Fatal(err)
+		d.t.Fatalf("unexpected failure: %v", err)
 	}
 }
 

cmd/tier/help.go

@@ -137,6 +137,9 @@ Flags:
 		set the org's trial period to the provided number of days. If
 		negative, the tial period will last indefinitely, and no other
 		phase will come after it.
+	--cancel
+		cancel the org's subscription. It is an error to provide a plan
+		or featurePlan with this flag.
 
 Global Flags:
 

cmd/tier/tier.go

@@ -256,6 +256,7 @@ func runTier(cmd string, args []string) (err error) {
 		fs := flag.NewFlagSet(cmd, flag.ExitOnError)
 		email := fs.String("email", "", "sets the customer email address")
 		trial := fs.Int("trial", 0, "sets the trial period in days")
+		cancel := fs.Bool("cancel", false, "cancels the subscription")
 		if err := fs.Parse(args); err != nil {
 			return err
 		}
@@ -268,6 +269,17 @@ func runTier(cmd string, args []string) (err error) {
 				Email: *email,
 			},
 		}
+
+		// the cancel must be used without arguments
+		if *cancel && fs.NArg() > 1 {
+			fmt.Fprintln(stderr, "tier: the -cancel flag must be used without arguments")
+			return errUsage
+		}
+
+		if *cancel {
+			p.Phases = []tier.Phase{{}}
+		}
+
 		var refs []string
 		if fs.NArg() > 1 {
 			refs = fs.Args()[1:]
@@ -290,6 +302,7 @@ func runTier(cmd string, args []string) (err error) {
 				p.Phases = []tier.Phase{{Features: refs}}
 			}
 		}
+
 		vlogf("subscribing %s to %v", org, refs)
 		return tc().Schedule(ctx, org, p)
 	case "phases":

cmd/tier/tier_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 	"time"
 
+	"golang.org/x/exp/slices"
 	"kr.dev/diff"
 	"tier.run/cmd/tier/cline"
 	"tier.run/profile"
@@ -489,6 +490,37 @@ func TestSubscribe(t *testing.T) {
 
 	tt.Run("subscribe", "org:test")
 	tt.GrepBothNot(".+", "unexpected output")
+
+	tt = testtier(t, okHandler(t))
+	tt.RunFail("subscribe", "--cancel", "org:test", "plan:free@2")
+	tt.GrepStderr("Usage:", ".*without arguments.*Usage:")
+
+	var got atomicSlice[string]
+	tt = testtier(t, func(w http.ResponseWriter, r *http.Request) {
+		t.Logf("got request: %s %s", r.Method, r.URL.Path)
+		switch {
+		case wants(r, "GET", "/v1/subscriptions"):
+			io.WriteString(w, `{
+				"data": [
+					{
+						"id": "sub_123",
+						"metadata": {
+							"tier.subscription": "default"
+						}
+					}
+				]
+			}`)
+		case wants(r, "DELETE", "/v1/subscriptions/sub_123"):
+			got.Append(r.URL.Path)
+		default:
+			io.WriteString(w, `{}`)
+		}
+	})
+
+	tt.Run("subscribe", "--cancel", "org:test")
+
+	want := []string{"/v1/subscriptions/sub_123"}
+	diff.Test(t, t.Errorf, got.Load(), want)
 }
 
 const responsePricesValidPlan = `
@@ -566,6 +598,27 @@ func chdir(t *testing.T, dir string) {
 	})
 }
 
-func wants(r *http.Request, method, path string) bool {
-	return r.Method == method && r.URL.Path == path
+func wants(r *http.Request, method, pattern string) bool {
+	pattern = "^" + pattern + "$"
+	rx := regexp.MustCompile(pattern)
+	return r.Method == method && rx.MatchString(r.URL.Path)
+}
+
+type atomicSlice[T any] struct {
+	mu sync.Mutex
+	v  []T
+}
+
+func (s *atomicSlice[T]) Append(v T) {
+	s.mu.Lock()
+	s.v = append(s.v, v)
+	s.mu.Unlock()
+}
+
+// Load returns a shallow clone of the slice.
+func (s *atomicSlice[T]) Load() []T {
+	s.mu.Lock()
+	v := slices.Clone(s.v)
+	s.mu.Unlock()
+	return v
 }

control/schedule.go

@@ -301,7 +301,7 @@ func isReleased(err error) bool {
 }
 
 func (c *Client) scheduleCancel(ctx context.Context, org string) (err error) {
-	defer errorfmt.Handlef("tier: ScheduleCancel: %q: %w", org, &err)
+	defer errorfmt.Handlef("tier: scheduleCancel: %q: %w", org, &err)
 	s, err := c.lookupSubscription(ctx, org, subscriptionNameTODO)
 	if err != nil {
 		return err