handler_test: add testApiRequest, testMailtoEvent

This does away with the need to pass a byte array to
fixture.handleApiRequest and fixture.handleMailtoEvent. This will, in
turn, make it easier to write more test without messing up a byte array.

Also introduces a new, but skipped, test case for a successful
/subscribe request. The plan is to test the individual smaller methods
more rigourously, then only add a few high-level request cases to cover
major flows. Several of these will duplicate, or eliminate, cases from
bin/smoke-test.sh.

handler/handler_test.go

@@ -1,7 +1,6 @@
 package handler
 
 import (
-	"fmt"
 	"net/http"
 	"testing"
 
@@ -11,6 +10,24 @@ import (
 	"gotest.tools/assert"
 )
 
+type testApiRequest struct {
+	RawPath string
+	Headers map[string]string
+	Body    string
+}
+
+type testMailtoEvent struct {
+	From         []string
+	To           []string
+	Subject      string
+	SpfVerdict   string
+	DkimVerdict  string
+	SpamVerdict  string
+	VirusVerdict string
+	DmarcVerdict string
+	DmarcPolicy  string
+}
+
 type testAgent struct {
 	Email       string
 	Uid         uuid.UUID
@@ -40,15 +57,18 @@ func (a *testAgent) Unsubscribe(
 }
 
 type fixture struct {
-	e Event
-	h *Handler
+	e  Event
+	ta *testAgent
+	h  *Handler
 }
 
 func newFixture() *fixture {
+	ta := &testAgent{}
 	return &fixture{
+		ta: ta,
 		h: NewHandler(
 			"mike-bland.com",
-			&testAgent{},
+			ta,
 			RedirectPaths{
 				"invalid",
 				"already-subscribed",
@@ -61,57 +81,100 @@ func newFixture() *fixture {
 }
 
 func (f *fixture) handleApiRequest(
-	data []byte,
+	testReq *testApiRequest,
 ) (*events.APIGatewayV2HTTPResponse, error) {
-	if err := f.e.UnmarshalJSON(data); err != nil {
-		return nil, err
-	} else if f.e.Type != ApiRequest {
-		return nil, fmt.Errorf("not an API request: %s", f.e.Type)
-	}
+	f.e.Type = ApiRequest
+	fReq := &f.e.ApiRequest
+	fReq.RawPath = testReq.RawPath
+	fReq.Headers = testReq.Headers
+	fReq.Body = testReq.Body
 	response, err := f.h.HandleEvent(&f.e)
 	return response.(*events.APIGatewayV2HTTPResponse), err
 }
 
-func (f *fixture) handleMailtoEvent(data []byte) (any, error) {
-	if err := f.e.UnmarshalJSON(data); err != nil {
-		return nil, err
-	} else if f.e.Type != MailtoEvent {
-		return nil, fmt.Errorf("not a mailto event: %s", f.e.Type)
-	}
+func (f *fixture) handleMailtoEvent(e *testMailtoEvent) (any, error) {
+	f.e.Type = MailtoEvent
+	ses := events.SimpleEmailService{}
+	headers := ses.Mail.CommonHeaders
+	receipt := &ses.Receipt
+
+	headers.From = e.From
+	headers.To = e.To
+	headers.Subject = e.Subject
+
+	receipt.SPFVerdict.Status = e.SpfVerdict
+	receipt.DKIMVerdict.Status = e.DkimVerdict
+	receipt.SpamVerdict.Status = e.SpamVerdict
+	receipt.VirusVerdict.Status = e.VirusVerdict
+	receipt.DMARCVerdict.Status = e.DmarcVerdict
+	receipt.DMARCPolicy = e.DmarcPolicy
+
+	f.e.MailtoEvent.Records = append(
+		f.e.MailtoEvent.Records, events.SimpleEmailRecord{SES: ses},
+	)
 	return f.h.HandleEvent(&f.e)
 }
 
-func TestIgnoreUnexpectedEvent(t *testing.T) {
-	f := newFixture()
+func TestHandleEvent(t *testing.T) {
+	t.Run("IgnoresUnexpectedEvent", func(t *testing.T) {
+		f := newFixture()
 
-	response, err := f.h.HandleEvent(&f.e)
+		response, err := f.h.HandleEvent(&f.e)
 
-	assert.NilError(t, err)
-	assert.Equal(t, nil, response)
+		assert.NilError(t, err)
+		assert.Equal(t, nil, response)
+	})
 }
 
-func TestApiRequestReturnsInvalidRequestLocationUntilImplemented(t *testing.T) {
-	f := newFixture()
-
-	response, err := f.handleApiRequest([]byte(`{
-		"rawPath": "/subscribe",
-		"body": "email=mbland%40acm.org"
-	}`))
-
-	assert.NilError(t, err)
-	assert.Equal(t, response.StatusCode, http.StatusSeeOther)
-	assert.Equal(t, response.Headers["Location"], f.h.Redirects[ops.Invalid])
+func TestSubscribeRequest(t *testing.T) {
+	t.Run("Successful", func(t *testing.T) {
+		t.Skip("not yet implemented")
+		f := newFixture()
+		f.ta.ReturnValue = ops.Subscribed
+
+		response, err := f.handleApiRequest(&testApiRequest{
+			RawPath: "/subscribe",
+			Headers: map[string]string{
+				"Content-Type": "application/x-www-form-urlencoded",
+			},
+			Body: "email=mbland%40acm.org",
+		})
+
+		assert.NilError(t, err)
+		assert.Equal(t, f.ta.Email, "mbland@acm.org")
+		assert.Equal(t, response.StatusCode, http.StatusSeeOther)
+		assert.Equal(
+			t, response.Headers["Location"], f.h.Redirects[ops.Subscribed],
+		)
+	})
+
+	t.Run("ReturnsInvalidRequestIfParsingFails", func(t *testing.T) {
+		f := newFixture()
+
+		response, err := f.handleApiRequest(&testApiRequest{
+			RawPath: "/subscribe",
+			Headers: map[string]string{
+				"Content-Type": "application/x-www-form-urlencoded",
+			},
+			Body: "email=mbland%20acm.org",
+		})
+
+		assert.NilError(t, err)
+		assert.Equal(t, f.ta.Email, "")
+		assert.Equal(t, response.StatusCode, http.StatusSeeOther)
+		assert.Equal(
+			t, response.Headers["Location"], f.h.Redirects[ops.Invalid],
+		)
+	})
 }
 
 func TestMailtoEventDoesNothingUntilImplemented(t *testing.T) {
 	f := newFixture()
 
-	response, err := f.handleMailtoEvent([]byte(`{
-		"Records": [{ "ses": { "mail": { "commonHeaders": {
-			"to": [ "unsubscribe@mike-bland.com" ],
-			"subject": "foo@bar.com UID"
-		}}}}]
-	}`))
+	response, err := f.handleMailtoEvent(&testMailtoEvent{
+		To:      []string{"unsubscribe@mike-bland.com"},
+		Subject: "foo@bar.com UID",
+	})
 
 	assert.NilError(t, err)
 	assert.Equal(t, nil, response)