Add HTTP handlers package

handlers/file_handler.go

@@ -0,0 +1,27 @@
+package handlers
+
+import (
+	"net/http"
+	"os"
+)
+
+// FileHandler returns a function to handle file requests. If the provided
+// notFoundFile argument is a valid path to a file, then that file is served
+// when the requested resource is not found. Set notFoundFile to an empty string
+// to serve Go's default "404 page not found" response when the requested
+// resource is not found.
+func FileHandler(notFoundFile string) func(http.ResponseWriter, *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if !doesPathExist(r) && notFoundFile != "" {
+			w.WriteHeader(http.StatusNotFound)
+			http.ServeFile(w, r, notFoundFile)
+			return
+		}
+		http.ServeFile(w, r, r.URL.Path[1:])
+	}
+}
+
+func doesPathExist(r *http.Request) bool {
+	_, err := os.Stat("." + r.URL.Path)
+	return err == nil
+}

handlers/file_handler_test.go

@@ -0,0 +1,78 @@
+package handlers
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestFileHandler(t *testing.T) {
+	type Want struct {
+		status int
+		body   string
+	}
+
+	type Test struct {
+		notFoundFile  string
+		requestedFile string
+		want          *Want
+	}
+
+	// Define test cases
+	tests := []Test{
+		{
+			notFoundFile:  "",
+			requestedFile: "/test-files/request-1.txt",
+			want: &Want{
+				status: http.StatusOK,
+				body:   "This file is used for testing.",
+			},
+		}, {
+			notFoundFile:  "",
+			requestedFile: "/some-file-that-does-not-exist.txt",
+			want: &Want{
+				status: http.StatusNotFound,
+				body:   "404 page not found\n",
+			},
+		}, {
+			notFoundFile:  "./test-files/custom-404.txt",
+			requestedFile: "/some-file-that-does-not-exist.txt",
+			want: &Want{
+				status: http.StatusNotFound,
+				body:   "Custom 404 page.",
+			},
+		},
+	}
+
+	// Loop over all test cases
+	for _, tc := range tests {
+		// Create a request to pass to the handler.
+		req, err := http.NewRequest("GET", tc.requestedFile, nil)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		// Setup handler with response recorder
+		rr := httptest.NewRecorder()
+		handler := http.HandlerFunc(FileHandler(tc.notFoundFile))
+		handler.ServeHTTP(rr, req)
+
+		// Check the status code is what we expect.
+		if status := rr.Code; status != tc.want.status {
+			t.Errorf(
+				"Handler returned wrong status code: want %v, but got %v.",
+				tc.want.status,
+				status,
+			)
+		}
+
+		// Check the response body is what we expect.
+		if body := rr.Body.String(); body != tc.want.body {
+			t.Errorf(
+				"Handler returned unexpected body: want \"%v\", but got \"%v\".",
+				tc.want.body,
+				body,
+			)
+		}
+	}
+}

handlers/test-files/custom-404.txt

@@ -0,0 +1 @@
+Custom 404 page.

handlers/test-files/request-1.txt

@@ -0,0 +1 @@
+This file is used for testing.

main.go

@@ -1,40 +1,25 @@
 package main
 
 import (
-	"fmt"
+	"log"
 	"net/http"
-	"os"
 	"strconv"
 
 	"github.com/samherrmann/serveit/flag"
+	"github.com/samherrmann/serveit/handlers"
 )
 
 func main() {
 	// Parse command-line flags into a configuration object
 	config := flag.Parse()
 	// Register file handler
-	http.HandleFunc("/", fileHandler(config.NotFoundFile))
+	http.HandleFunc("/", handlers.FileHandler(config.NotFoundFile))
 	// Start HTTP server
 	listenAndServe(config.Port)
 }
 
-func fileHandler(notFoundFile string) func(http.ResponseWriter, *http.Request) {
-	return func(w http.ResponseWriter, r *http.Request) {
-		if !doesPathExist(r) && notFoundFile != "" {
-			http.ServeFile(w, r, notFoundFile)
-			return
-		}
-		http.ServeFile(w, r, r.URL.Path[1:])
-	}
-}
-
-func doesPathExist(r *http.Request) bool {
-	_, err := os.Stat("." + r.URL.Path)
-	return err == nil
-}
-
 func listenAndServe(port int) {
 	addr := ":" + strconv.Itoa(port)
-	fmt.Println("Serving current directory on port " + addr)
-	panic(http.ListenAndServe(addr, nil))
+	log.Println("Serving current directory on port " + addr)
+	log.Fatalln(http.ListenAndServe(addr, nil))
 }