Merge pull request #6 from Shivam010/dev

feat: Makefile introduced, tests added

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Build Check
+name: build
 on: [push]
 jobs:
 
@@ -7,20 +7,19 @@ jobs:
     runs-on: ubuntu-latest
     steps:
 
-    - name: Set up Go 1.12
-      uses: actions/setup-go@v1
-      with:
-        go-version: 1.12
-      id: go
+      - name: Set up Go 1.12
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.12
+        id: go
 
-    - name: Check out code into the Go module directory
-      uses: actions/checkout@v1
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v1
 
-    - name: Get dependencies
-      run: |
-        go get -v -t -d ./...
-
-    - name: Build
-      run: go build -v .
+      - name: Build and Test
+        # `test` firsts triggers `build` which triggers `clean`
+        # which in turns triggers `vet` and `fmt` as a series
+        # of operations
+        run: make test
 
 

Makefile

@@ -0,0 +1,22 @@
+GO = GO111MODULE=on go
+
+fmt:
+	${GO} fmt ./...
+
+vet: fmt
+	${GO} vet ./...
+
+clean: vet
+	rm -rf ./bin
+	${GO} mod tidy
+
+build: clean
+	${GO} build -o ./bin/bypass-cors ./...
+
+test: build
+	${GO} test -v -cover ./...
+
+run: clean
+	${GO} run ./... -p 80
+
+.PHONY: run build clean vet fmt

go.mod

@@ -2,4 +2,4 @@ module github.com/Shivam010/bypass-cors
 
 go 1.12
 
-require github.com/rs/cors v1.6.0
+require github.com/google/go-cmp v0.3.1

go.sum

@@ -1,2 +1,2 @@
-github.com/rs/cors v1.6.0 h1:G9tHG9lebljV9mfp9SNPDL36nCDxmo3zTlAf1YgvzmI=
-github.com/rs/cors v1.6.0/go.mod h1:gFx+x8UowdsKA9AchylcLynDq+nNFfI8FkUZdN/jGCU=
+github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=

helper.go

@@ -60,38 +60,53 @@ func (e *Error) StatusCode() int {
 	return e.Code
 }
 
+const (
+	// headers
+	VaryHeader   = "Vary"
+	OriginHeader = "Origin"
+	QuoteHeader  = "quote"
+	// Access Control headers
+	AllowOrigin      = "Access-Control-Allow-Origin"
+	AllowMethods     = "Access-Control-Allow-Methods"
+	AllowHeaders     = "Access-Control-Allow-Headers"
+	AllowCredentials = "Access-Control-Allow-Credentials"
+	// Access control request headers
+	RequestMethod  = "Access-Control-Request-Method"
+	RequestHeaders = "Access-Control-Request-Headers"
+)
+
 // defaultHeaders handles a general request and add/set corresponding headers
 func defaultHeaders(w http.ResponseWriter, r *http.Request) {
 	headers := w.Header()
-	origin := r.Header.Get("Origin")
+	origin := r.Header.Get(OriginHeader)
 
 	// Adding Vary header - for http cache
-	headers.Add("Vary", "Origin")
+	headers.Add(VaryHeader, OriginHeader)
 
 	// quote
-	headers.Set("quote", "Be Happy :)")
+	headers.Set(QuoteHeader, "Be Happy :)")
 
 	// Allowing only the requester - can be set to "*" too
-	headers.Set("Access-Control-Allow-Origin", origin)
+	headers.Set(AllowOrigin, origin)
 	// Always allowing credentials - just for the sake of proxy request
-	headers.Set("Access-Control-Allow-Credentials", "true")
+	headers.Set(AllowCredentials, "true")
 }
 
 // headersForPreflight handles the pre-flight cors request and add/set the
 // corresponding headers
 func headersForPreflight(w http.ResponseWriter, r *http.Request) {
 	headers := w.Header()
-	reqMethod := r.Header.Get("Access-Control-Request-Method")
-	reqHeaders := r.Header.Get("Access-Control-Request-Headers")
+	reqMethod := r.Header.Get(RequestMethod)
+	reqHeaders := r.Header.Get(RequestHeaders)
 
 	// Vary header - for http cache
-	headers.Add("Vary", "Access-Control-Request-Method")
-	headers.Add("Vary", "Access-Control-Request-Headers")
+	headers.Add(VaryHeader, RequestMethod)
+	headers.Add(VaryHeader, RequestHeaders)
 
 	// Allowing the requested method
-	headers.Set("Access-Control-Allow-Methods", strings.ToUpper(reqMethod))
+	headers.Set(AllowMethods, strings.ToUpper(reqMethod))
 	// Allowing the requested headers
-	headers.Set("Access-Control-Allow-Headers", reqHeaders)
+	headers.Set(AllowHeaders, reqHeaders)
 }
 
 // addHeaders handles request and set headers accordingly. It returns true if
@@ -100,7 +115,7 @@ func addHeaders(w http.ResponseWriter, r *http.Request) bool {
 
 	defaultHeaders(w, r)
 
-	if r.Method == http.MethodOptions && r.Header.Get("Access-Control-Request-Method") != "" {
+	if r.Method == http.MethodOptions && r.Header.Get(RequestMethod) != "" {
 		headersForPreflight(w, r)
 		Return(w, &ValuerStruct{Code: http.StatusOK})
 		return true
@@ -109,7 +124,7 @@ func addHeaders(w http.ResponseWriter, r *http.Request) bool {
 	return false
 }
 
-// getRequestURL returns the reuested URL to bypass-cors
+// getRequestURL returns the requested URL to bypass-cors
 func getRequestURL(w http.ResponseWriter, r *http.Request) *url.URL {
 
 	if r.URL.Path == "" || r.URL.Path == "/" {

init.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"flag"
+)
+
+const (
+	shortHand = " (short hand)"
+
+	defaultPort = "8080"
+	usagePort   = "PORT at which the server will run"
+)
+
+var (
+	// PORT at which the server will run (default: 8080),
+	// can be modified using flags:
+	// 	`-port 80` or `-p 80`
+	PORT string
+)
+
+func init() {
+	flag.StringVar(&PORT, "port", defaultPort, usagePort)
+	flag.StringVar(&PORT, "p", defaultPort, usagePort+shortHand)
+}

main.go

@@ -7,7 +7,6 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	"os"
 )
 
 type handler struct{}
@@ -60,6 +59,11 @@ func (*handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	fmt.Println("UserClient --> bypass-cors -->", req.URL.Host)
 
+	// Populate the rest of the header
+	for k, v := range r.Header {
+		req.Header.Add(k, v[0])
+	}
+
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		fmt.Println("Request Failed:", err)
@@ -97,14 +101,13 @@ func (*handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 }
 
 func main() {
-	var PORT string
-	if PORT = os.Getenv("PORT"); PORT == "" {
-		flag.StringVar(&PORT, "p", "8080", "PORT at which the server will run")
-	}
+
+	// parse all flags set in `init`
 	flag.Parse()
 
-	fmt.Printf("\nRunning Proxy ByPass Cors Server at port = %v...\n\n", PORT)
+	fmt.Printf("\nStarting Proxy ByPass-Cors Server at port(:%v)...\n\n", PORT)
+
 	if err := http.ListenAndServe(":"+PORT, &handler{}); err != nil {
-		log.Println("\n\nPanic", err)
+		log.Println("\n\nPanics", err)
 	}
 }