Feature 04 task 5: Async job runner and GET /api/v1/jobs/{id} (#29)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com>
Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>

internal/server/jobs.go

@@ -0,0 +1,29 @@
+package server
+
+import (
+	"errors"
+	"log/slog"
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+)
+
+// getJob serves GET /api/v1/jobs/{id}: the job's id, kind, status, latest
+// result and error.
+func getJob(logger *slog.Logger, runner *jobs.Runner) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		job, err := runner.Get(r.Context(), chi.URLParam(r, "id"))
+		if errors.Is(err, jobs.ErrNotFound) {
+			writeError(w, r, logger, http.StatusNotFound, "not_found", "job not found")
+			return
+		}
+		if err != nil {
+			logger.ErrorContext(r.Context(), "get job", "error", err)
+			writeError(w, r, logger, http.StatusInternalServerError, "internal", "internal error")
+			return
+		}
+		writeJSON(w, r, logger, http.StatusOK, job)
+	}
+}

internal/server/jobs_test.go

@@ -0,0 +1,153 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"maps"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"testing"
+	"time"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/store"
+)
+
+type draftPayload struct{}
+
+type draftResult struct {
+	Days int `json:"days"`
+}
+
+func (d draftResult) PublicJSON() ([]byte, error) { return json.Marshal(d) }
+
+// startedRunner registers a "draft" kind that publishes {"days":1}, waits
+// for release and returns {"days":7}, or fails with a *jobs.Failure when
+// fail is closed first. It starts the runner and stops it when the test ends.
+func startedRunner(t *testing.T, release, fail <-chan struct{}) (*jobs.Runner, *jobs.Kind[draftPayload]) {
+	t.Helper()
+	runner := newTestRunner(t)
+	kind, err := jobs.Register(runner, "draft", func(ctx context.Context, _ draftPayload, publish func(draftResult) error) (draftResult, error) {
+		if err := publish(draftResult{Days: 1}); err != nil {
+			return draftResult{}, err
+		}
+		select {
+		case <-release:
+			return draftResult{Days: 7}, nil
+		case <-fail:
+			return draftResult{}, &jobs.Failure{Code: "no_regulars"}
+		case <-ctx.Done():
+			return draftResult{}, ctx.Err()
+		}
+	}, "no_regulars")
+	if err != nil {
+		t.Fatal(err)
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	if err := runner.Start(ctx); err != nil {
+		cancel()
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		cancel()
+		runner.Wait()
+	})
+	return runner, kind
+}
+
+// pollJob GETs the job until want accepts the body, failing after five
+// seconds.
+func pollJob(t *testing.T, h http.Handler, id string, want func(map[string]any) bool) map[string]any {
+	t.Helper()
+	deadline := time.Now().Add(5 * time.Second)
+	for {
+		rec, body := serve(t, h, signedIn(http.MethodGet, "/api/v1/jobs/"+id, nil))
+		if rec.Code != http.StatusOK {
+			t.Fatalf("status = %d, want 200: %s", rec.Code, rec.Body)
+		}
+		if want(body) {
+			if keys := slices.Sorted(maps.Keys(body)); !slices.Equal(keys, []string{"error", "id", "kind", "result", "status"}) {
+				t.Errorf("body fields = %v, want id, kind, status, result, error", keys)
+			}
+			return body
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("job %s never reached the expected state; last %v", id, body)
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+}
+
+func resultDays(body map[string]any) float64 {
+	result, _ := body["result"].(map[string]any)
+	days, _ := result["days"].(float64)
+	return days
+}
+
+func TestGetJobShowsProgressThenResult(t *testing.T) {
+	t.Parallel()
+	release := make(chan struct{})
+	runner, kind := startedRunner(t, release, nil)
+	router := newTestRouterWith(t, "dev", newTestSettings(t), runner)
+	id, err := kind.Enqueue(context.Background(), draftPayload{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	mid := pollJob(t, router, id, func(b map[string]any) bool { return resultDays(b) == 1 })
+	if mid["id"] != id || mid["kind"] != "draft" || mid["status"] != "running" || mid["error"] != nil {
+		t.Errorf("mid-run body = %v, want running draft job %s with no error", mid, id)
+	}
+
+	close(release)
+	done := pollJob(t, router, id, func(b map[string]any) bool { return b["status"] == "succeeded" })
+	if resultDays(done) != 7 || done["error"] != nil {
+		t.Errorf("finished body = %v, want result {\"days\":7} and no error", done)
+	}
+}
+
+func TestGetJobShowsFailure(t *testing.T) {
+	t.Parallel()
+	fail := make(chan struct{})
+	close(fail)
+	runner, kind := startedRunner(t, nil, fail)
+	router := newTestRouterWith(t, "dev", newTestSettings(t), runner)
+	id, err := kind.Enqueue(context.Background(), draftPayload{})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	body := pollJob(t, router, id, func(b map[string]any) bool { return b["status"] == "failed" })
+	if body["error"] != "no_regulars" {
+		t.Errorf("error = %v, want the Failure code", body["error"])
+	}
+}
+
+func TestGetJobUnknownIDIsNotFound(t *testing.T) {
+	t.Parallel()
+	router := newTestRouter(t, "dev")
+
+	rec, _ := serve(t, router, signedIn(http.MethodGet, "/api/v1/jobs/"+store.NewID(), nil))
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want 404", rec.Code)
+	}
+	var body errorBody
+	if err := json.Unmarshal(rec.Body.Bytes(), &body); err != nil {
+		t.Fatal(err)
+	}
+	if want := (errorBody{Error: apiError{Code: "not_found", Message: "job not found"}}); body != want {
+		t.Errorf("body = %+v, want %+v", body, want)
+	}
+}
+
+func TestGetJobRequiresSession(t *testing.T) {
+	t.Parallel()
+	router := newTestRouter(t, "dev")
+
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/api/v1/jobs/"+store.NewID(), nil))
+	if rec.Code != http.StatusUnauthorized {
+		t.Errorf("status = %d, want 401", rec.Code)
+	}
+}

internal/server/login_test.go

@@ -83,7 +83,7 @@ func newLoginRouter(t *testing.T, issuer string) http.Handler {
 		t.Fatal(err)
 	}
 	r, err := NewRouter(logger, "dev", trusted, flow, sessions, newTestSettings(t),
-		fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
+		newTestRunner(t), fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
 	if err != nil {
 		t.Fatal(err)
 	}

internal/server/origin_test.go

@@ -45,7 +45,7 @@ func newOriginRouter(t *testing.T, logs io.Writer) http.Handler {
 	}
 	logger := slog.New(forwarded.LogHandler(slog.NewJSONHandler(logs, nil)))
 	r, err := NewRouter(logger, "dev", trusted, probeAuth{}, stubSessions{}, newTestSettings(t),
-		fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
+		newTestRunner(t), fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
 	if err != nil {
 		t.Fatal(err)
 	}

internal/server/server.go

@@ -13,6 +13,7 @@ import (
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/forwarded"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/frontend"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
 )
 
 // reservedPrefixes are owned by the API router and are never answered with the
@@ -28,13 +29,17 @@ type RouteMounter interface {
 // has its client address and scheme resolved, honouring forwarded headers
 // only from a peer in trusted (see resolveOrigin). version is reported by
 // GET /health; auth mounts the /auth routes; sessions guards /api/v1 and
-// /media; settings serves /api/v1/settings/household; assets is the web build
+// /media; settings serves /api/v1/settings/household; runner serves
+// /api/v1/jobs/{id}; assets is the web build
 // served for every other GET. /health, /auth and the web build are public.
 // Requests to /api/v1 other than GET also need the session's CSRF token in CSRFHeader.
-func NewRouter(logger *slog.Logger, version string, trusted forwarded.Trusted, auth RouteMounter, sessions SessionLookup, settings *household.SettingsService, assets fs.FS) (http.Handler, error) {
+func NewRouter(logger *slog.Logger, version string, trusted forwarded.Trusted, auth RouteMounter, sessions SessionLookup, settings *household.SettingsService, runner *jobs.Runner, assets fs.FS) (http.Handler, error) {
 	if settings == nil {
 		return nil, errors.New("server: nil household settings service")
 	}
+	if runner == nil {
+		return nil, errors.New("server: nil job runner")
+	}
 	notFound := apiErrorHandler(logger, http.StatusNotFound, "not_found", "not found")
 	methodNotAllowed := apiErrorHandler(logger, http.StatusMethodNotAllowed, "method_not_allowed", "method not allowed")
 
@@ -63,6 +68,7 @@ func NewRouter(logger *slog.Logger, version string, trusted forwarded.Trusted, a
 	apiV1.Get("/me", me(logger))
 	apiV1.Get("/settings/household", getHouseholdSettings(logger, settings))
 	apiV1.Patch("/settings/household", patchHouseholdSettings(logger, settings))
+	apiV1.Get("/jobs/{id}", getJob(logger, runner))
 	r.Route("/api", func(r chi.Router) {
 		r.MethodNotAllowed(methodNotAllowed)
 		r.NotFound(notFound)

internal/server/server_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/go-chi/chi/v5"
 
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/store"
 	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/migrations"
 )
@@ -27,17 +28,17 @@ const (
 
 func newTestRouter(t *testing.T, version string) http.Handler {
 	t.Helper()
-	return newTestRouterWith(t, version, newTestSettings(t))
+	return newTestRouterWith(t, version, newTestSettings(t), newTestRunner(t))
 }
 
-func newTestRouterWith(t *testing.T, version string, settings *household.SettingsService) http.Handler {
+func newTestRouterWith(t *testing.T, version string, settings *household.SettingsService, runner *jobs.Runner) http.Handler {
 	t.Helper()
 	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
 	assets := fstest.MapFS{
 		"index.html":             {Data: []byte(fixtureIndex)},
 		"assets/index-AbC123.js": {Data: []byte(fixtureAsset)},
 	}
-	r, err := NewRouter(logger, version, nil, stubAuth{}, stubSessions{}, settings, assets)
+	r, err := NewRouter(logger, version, nil, stubAuth{}, stubSessions{}, settings, runner, assets)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -70,9 +71,8 @@ func TestAuthRoutesMounted(t *testing.T) {
 	}
 }
 
-// newTestSettings returns a settings service over a migrated temp database
-// seeded with zone America/New_York.
-func newTestSettings(t *testing.T) *household.SettingsService {
+// newTestStore returns a migrated temp database, closed when the test ends.
+func newTestStore(t *testing.T) *store.Store {
 	t.Helper()
 	ctx := context.Background()
 	st, err := store.Open(ctx, t.TempDir())
@@ -87,21 +87,49 @@ func newTestSettings(t *testing.T) *household.SettingsService {
 	if err := store.Migrate(ctx, st.Writer, migrations.FS); err != nil {
 		t.Fatal(err)
 	}
-	if err := household.SeedSettings(ctx, st, "America/New_York"); err != nil {
+	return st
+}
+
+// newTestSettings returns a settings service over a migrated temp database
+// seeded with zone America/New_York.
+func newTestSettings(t *testing.T) *household.SettingsService {
+	t.Helper()
+	st := newTestStore(t)
+	if err := household.SeedSettings(context.Background(), st, "America/New_York"); err != nil {
 		t.Fatal(err)
 	}
 	return household.NewSettingsService(st)
 }
 
+// newTestRunner returns an unstarted job runner over a migrated temp
+// database.
+func newTestRunner(t *testing.T) *jobs.Runner {
+	t.Helper()
+	runner, err := jobs.NewRunner(newTestStore(t), slog.New(slog.NewTextHandler(io.Discard, nil)), 1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return runner
+}
+
 func TestNewRouterRequiresSettings(t *testing.T) {
 	t.Parallel()
 
 	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
-	if _, err := NewRouter(logger, "dev", nil, stubAuth{}, stubSessions{}, nil, fstest.MapFS{"index.html": {}}); err == nil {
+	if _, err := NewRouter(logger, "dev", nil, stubAuth{}, stubSessions{}, nil, newTestRunner(t), fstest.MapFS{"index.html": {}}); err == nil {
 		t.Fatal("NewRouter accepted a nil settings service")
 	}
 }
 
+func TestNewRouterRequiresJobRunner(t *testing.T) {
+	t.Parallel()
+
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	if _, err := NewRouter(logger, "dev", nil, stubAuth{}, stubSessions{}, newTestSettings(t), nil, fstest.MapFS{"index.html": {}}); err == nil {
+		t.Fatal("NewRouter accepted a nil job runner")
+	}
+}
+
 func TestHealth(t *testing.T) {
 	t.Parallel()
 

internal/server/settings_test.go

@@ -84,7 +84,7 @@ func TestGetHouseholdSettings(t *testing.T) {
 func TestPatchHouseholdSettings(t *testing.T) {
 	t.Parallel()
 	settings := newTestSettings(t)
-	router := newTestRouterWith(t, "dev", settings)
+	router := newTestRouterWith(t, "dev", settings, newTestRunner(t))
 
 	var notified []household.Settings
 	settings.Subscribe(func(s household.Settings) { notified = append(notified, s) })
@@ -146,7 +146,7 @@ func TestPatchHouseholdSettingsRejected(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 			settings := newTestSettings(t)
-			router := newTestRouterWith(t, "dev", settings)
+			router := newTestRouterWith(t, "dev", settings, newTestRunner(t))
 			notified := 0
 			settings.Subscribe(func(household.Settings) { notified++ })
 
@@ -216,7 +216,7 @@ func TestHouseholdSettingsWithRealSession(t *testing.T) {
 	}
 	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
 	router, err := NewRouter(logger, "dev", nil, stubAuth{}, sessions, household.NewSettingsService(st),
-		fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
+		newTestRunner(t), fstest.MapFS{"index.html": {Data: []byte(fixtureIndex)}})
 	if err != nil {
 		t.Fatal(err)
 	}