chore: handler tests (#9)

go.mod

@@ -1,3 +1,5 @@
 module github.com/notnmeyer/mockpi
 
 go 1.20
+
+require github.com/spf13/pflag v1.0.5

go.sum

@@ -0,0 +1,2 @@
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=

main.go

@@ -6,41 +6,53 @@ import (
 	"net/http"
 	"os"
 	"strconv"
-)
 
-func main() {
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		var (
-			contentType  = "application/json; charset=utf-8"
-			responseBody = r.Header["X-Response-Json"][0]
-			responseCode int
-		)
+	flag "github.com/spf13/pflag"
+)
 
-		responseCode, err := validateResponseCode(r.Header)
-		if err != nil {
-			responseBody = err.Error()
-			contentType = "text/plain; charset=utf-8"
-		}
+type config struct {
+	port int
+}
 
-		if !isJSON(responseBody) {
-			responseBody = fmt.Errorf("x-response-json must be valid JSON").Error()
-			responseCode = http.StatusBadRequest
-			contentType = "text/plain; charset=utf-8"
-		}
+var c config
 
-		w.Header().Set("Content-Type", contentType)
-		w.WriteHeader(responseCode)
-		w.Write([]byte(responseBody))
-	})
+func init() {
+	flag.IntVarP(&c.port, "port", "p", 8080, "the listen port")
+	flag.Parse()
+}
 
-	listenAddr := ":8080"
+func main() {
+	http.HandleFunc("/", handler)
+	listenAddr := fmt.Sprintf(":%d", c.port)
 	fmt.Printf("Listening on %s...\n", listenAddr)
 	if err := http.ListenAndServe(listenAddr, nil); err != nil {
 		fmt.Println("server error: ", err)
 		os.Exit(1)
 	}
 }
 
+func handler(w http.ResponseWriter, r *http.Request) {
+	var (
+		contentType  = "application/json; charset=utf-8"
+		responseBody = r.Header["X-Response-Json"][0]
+		responseCode int
+	)
+
+	responseCode, err := validateResponseCode(r.Header)
+	if err != nil {
+		responseBody = err.Error()
+		contentType = "text/plain; charset=utf-8"
+	} else if !isJSON(responseBody) {
+		responseBody = fmt.Errorf("x-response-json must be valid JSON").Error()
+		responseCode = http.StatusBadRequest
+		contentType = "text/plain; charset=utf-8"
+	}
+
+	w.Header().Set("Content-Type", contentType)
+	w.WriteHeader(responseCode)
+	w.Write([]byte(responseBody))
+}
+
 func validateResponseCode(header map[string][]string) (int, error) {
 	if val, exists := header["X-Response-Code"]; exists {
 		// verify its a number

main_test.go

@@ -1,6 +1,115 @@
 package main
 
-import "testing"
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHandlerValidRequest(t *testing.T) {
+	expectedContentType := "application/json; charset=utf-8"
+	expectedResponseBody := `{"foo":"bar"}`
+	expectedResponseCode := http.StatusTeapot
+
+	// set up the request
+	req, err := http.NewRequest("POST", "/test", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Add("X-Response-Json", expectedResponseBody)
+	req.Header.Add("X-Response-Code", fmt.Sprint(expectedResponseCode))
+
+	// make the request
+	rr := httptest.NewRecorder()
+	h := http.HandlerFunc(handler)
+	h.ServeHTTP(rr, req)
+
+	// status code
+	if status := rr.Code; status != expectedResponseCode {
+		t.Errorf("handler returned wrong status code: got '%d' want '%d'", status, expectedResponseCode)
+	}
+
+	// response body
+	if rr.Body.String() != expectedResponseBody {
+		t.Errorf("handler returned unexpected body: got '%s' want '%s'", rr.Body.String(), expectedResponseBody)
+	}
+
+	// content-type
+	if rr.Header()["Content-Type"][0] != expectedContentType {
+		t.Errorf("handler returned wrong content-type: got '%s' wanted '%s'", rr.Header()["Content-Type"][0], expectedContentType)
+	}
+}
+
+func TestHandlerWithInvalidXResponseJson(t *testing.T) {
+	expectedContentType := "text/plain; charset=utf-8"
+	invalidResponseBody := `{"foo":bar}`
+	expectedResponseBody := "x-response-json must be valid JSON"
+	expectedResponseCode := http.StatusBadRequest
+
+	// set up the request
+	req, err := http.NewRequest("POST", "/test", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Add("X-Response-Json", invalidResponseBody)
+	req.Header.Add("X-Response-Code", fmt.Sprint(expectedResponseCode))
+
+	// make the request
+	rr := httptest.NewRecorder()
+	h := http.HandlerFunc(handler)
+	h.ServeHTTP(rr, req)
+
+	// status code
+	if status := rr.Code; status != expectedResponseCode {
+		t.Errorf("handler returned wrong status code: got '%d' want '%d'", status, expectedResponseCode)
+	}
+
+	// response body
+	if rr.Body.String() != expectedResponseBody {
+		t.Errorf("handler returned unexpected body: got '%s' want '%s'", rr.Body.String(), expectedResponseBody)
+	}
+
+	// content-type
+	if rr.Header()["Content-Type"][0] != expectedContentType {
+		t.Errorf("handler returned wrong content-type: got '%s' wanted '%s'", rr.Header()["Content-Type"][0], expectedContentType)
+	}
+}
+
+func TestHandlerWithInvalidXResponseCode(t *testing.T) {
+	expectedContentType := "text/plain; charset=utf-8"
+	expectedResponseBody := "x-response-code must be a number\n"
+	invalidResponseCode := "blah"
+	expectedResponseCode := http.StatusBadRequest
+
+	// set up the request
+	req, err := http.NewRequest("POST", "/test", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req.Header.Add("X-Response-Json", "{}")
+	req.Header.Add("X-Response-Code", invalidResponseCode)
+
+	// make the request
+	rr := httptest.NewRecorder()
+	h := http.HandlerFunc(handler)
+	h.ServeHTTP(rr, req)
+
+	// status code
+	if status := rr.Code; status != expectedResponseCode {
+		t.Errorf("handler returned wrong status code: got '%d' want '%d'", status, expectedResponseCode)
+	}
+
+	// response body
+	if rr.Body.String() != expectedResponseBody {
+		t.Errorf("handler returned unexpected body: got '%s' want '%s'", rr.Body.String(), expectedResponseBody)
+	}
+
+	// content-type
+	if rr.Header()["Content-Type"][0] != expectedContentType {
+		t.Errorf("handler returned wrong content-type: got '%s' wanted '%s'", rr.Header()["Content-Type"][0], expectedContentType)
+	}
+}
 
 func TestValidateResponseCode(t *testing.T) {
 	valid := map[string][]string{
@@ -16,6 +125,13 @@ func TestValidateResponseCode(t *testing.T) {
 	if _, err := validateResponseCode(invalid); err == nil {
 		t.Errorf("expected %v to be an invalid response code\n", invalid)
 	}
+
+	invalidStr := map[string][]string{
+		"X-Response-Code": {"hello"},
+	}
+	if _, err := validateResponseCode(invalidStr); err == nil {
+		t.Errorf("expected %v to be an invalid response code\n", invalid)
+	}
 }
 
 func TestIsJSON(t *testing.T) {