pkg/server/middleware_test.go

@@ -0,0 +1,181 @@
+package server
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"dance-lessons-coach/pkg/auth"
+	"dance-lessons-coach/pkg/user"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// fakeTokenValidator is a minimal tokenValidator stub.
+type fakeTokenValidator struct {
+	validUser *user.User
+	err       error
+	seen      string // captures the last token passed in
+}
+
+func (f *fakeTokenValidator) ValidateJWT(ctx context.Context, token string) (*user.User, error) {
+	f.seen = token
+	if f.err != nil {
+		return nil, f.err
+	}
+	return f.validUser, nil
+}
+
+// nextHandler returns 200 with a flag in body indicating whether a user
+// was injected into context.
+func nextHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		u, ok := auth.GetAuthenticatedUserFromContext(r.Context())
+		if ok && u != nil {
+			w.Header().Set("X-User", u.Username)
+		}
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("ok"))
+	})
+}
+
+func TestOptionalHandler_NoHeader_PassesThrough(t *testing.T) {
+	fv := &fakeTokenValidator{}
+	mw := NewAuthMiddleware(fv).OptionalHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Empty(t, rec.Header().Get("X-User"), "no user expected when no Authorization header")
+	assert.Empty(t, fv.seen, "validator should not have been called")
+}
+
+func TestOptionalHandler_MalformedHeader_PassesThrough(t *testing.T) {
+	fv := &fakeTokenValidator{}
+	mw := NewAuthMiddleware(fv).OptionalHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "Basic xxx")
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Empty(t, rec.Header().Get("X-User"))
+	assert.Empty(t, fv.seen, "validator should not have been called for non-Bearer scheme")
+}
+
+func TestOptionalHandler_BearerCaseInsensitive(t *testing.T) {
+	fv := &fakeTokenValidator{validUser: &user.User{Username: "alice"}}
+	mw := NewAuthMiddleware(fv).OptionalHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "bearer abc123") // lowercase
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "alice", rec.Header().Get("X-User"), "case-insensitive Bearer per RFC 6750")
+	assert.Equal(t, "abc123", fv.seen)
+}
+
+func TestOptionalHandler_InvalidJWT_PassesThrough(t *testing.T) {
+	fv := &fakeTokenValidator{err: errors.New("bad signature")}
+	mw := NewAuthMiddleware(fv).OptionalHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "Bearer xxx")
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code, "optional auth never returns 401")
+	assert.Empty(t, rec.Header().Get("X-User"))
+}
+
+func TestOptionalHandler_ValidJWT_InjectsUser(t *testing.T) {
+	fv := &fakeTokenValidator{validUser: &user.User{ID: 7, Username: "bob"}}
+	mw := NewAuthMiddleware(fv).OptionalHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "Bearer goodtoken")
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "bob", rec.Header().Get("X-User"))
+	assert.Equal(t, "goodtoken", fv.seen)
+}
+
+func TestRequiredHandler_NoHeader_Returns401(t *testing.T) {
+	fv := &fakeTokenValidator{}
+	mw := NewAuthMiddleware(fv).RequiredHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Contains(t, rec.Header().Get("WWW-Authenticate"), "Bearer", "RFC 6750 challenge header")
+	assert.Contains(t, rec.Body.String(), "unauthorized")
+}
+
+func TestRequiredHandler_InvalidJWT_Returns401WithErrorTag(t *testing.T) {
+	fv := &fakeTokenValidator{err: errors.New("expired")}
+	mw := NewAuthMiddleware(fv).RequiredHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "Bearer xxx")
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Contains(t, rec.Header().Get("WWW-Authenticate"), `error="invalid_token"`)
+}
+
+func TestRequiredHandler_ValidJWT_PassesThrough(t *testing.T) {
+	fv := &fakeTokenValidator{validUser: &user.User{Username: "carol"}}
+	mw := NewAuthMiddleware(fv).RequiredHandler(nextHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "/foo", nil)
+	req.Header.Set("Authorization", "Bearer goodtoken")
+	rec := httptest.NewRecorder()
+	mw.ServeHTTP(rec, req)
+
+	require.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "carol", rec.Header().Get("X-User"))
+}
+
+func TestExtractBearerToken_EdgeCases(t *testing.T) {
+	cases := []struct {
+		in  string
+		out string
+		ok  bool
+	}{
+		{"", "", false},
+		{"Bearer ", "", true}, // empty token, but matches the prefix — caller decides
+		{"Bearer xxx", "xxx", true},
+		{"bearer xxx", "xxx", true}, // case-insensitive
+		{"BEARER xxx", "xxx", true},
+		{"Basic xxx", "", false},
+		{"Bearer", "", false}, // no separating space
+		{"Bear", "", false},
+	}
+	for _, c := range cases {
+		t.Run(c.in, func(t *testing.T) {
+			tok, ok := extractBearerToken(c.in)
+			assert.Equal(t, c.ok, ok)
+			assert.Equal(t, c.out, tok)
+		})
+	}
+}
+
+func TestFirstWord(t *testing.T) {
+	assert.Equal(t, "Bearer", firstWord("Bearer xxx"))
+	assert.Equal(t, "Basic", firstWord("Basic\tabc"))
+	assert.Equal(t, "Token", firstWord("Token"))
+	assert.Equal(t, "", firstWord(""))
+}