Add Download handler test for redirects and fix imports (#15)

Author: suyashkumar

.github/workflows/go.yml

@@ -22,4 +22,8 @@ jobs:
 
     - name: Build
       run: |
-            go build ./...
+            go build ./...
+
+    - name: Test
+      run: |
+        go test ./...

go.mod

@@ -4,7 +4,6 @@ go 1.20
 
 require (
 	github.com/julienschmidt/httprouter v1.3.0
-	github.com/suyashkumar/bin v1.3.1
 	golang.org/x/crypto v0.6.0
 )
 

handlers/download.go

@@ -17,7 +17,7 @@ import (
 	"strings"
 
 	"github.com/julienschmidt/httprouter"
-	"github.com/suyashkumar/bin/releases"
+	"github.com/suyashkumar/getbin/releases"
 )
 
 // OS is an enum representing an operating system variant

handlers/download_test.go

@@ -0,0 +1,128 @@
+package handlers
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/julienschmidt/httprouter"
+	"github.com/suyashkumar/getbin/releases"
+)
+
+var errStopRedirect = errors.New("an error to stop following redirects")
+var defaultGithubAPIResponse = []byte(`[{ 
+	  "assets": [
+		   {"browser_download_url": "http://localhost/some-file-darwin-x86.tar.gz", "content_type": "application/x-gzip"},
+		   {"browser_download_url": "http://localhost/some-file-windows-x86.tar.gz", "content_type": "application/x-gzip"},
+		   {"browser_download_url": "http://localhost/some-file-linux-x86.tar.gz", "content_type": "application/x-gzip"}
+	  ]
+ }]`)
+
+func TestDownload_Redirect(t *testing.T) {
+	cases := []struct {
+		name              string
+		requestPath       string
+		userAgent         string
+		githubAPIResponse []byte
+		wantRedirect      string
+	}{
+		{
+			name:              "darwin option",
+			requestPath:       "/username/repo?os=darwin",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-darwin-x86.tar.gz",
+		},
+		{
+			name:              "darwin user-agent",
+			requestPath:       "/username/repo",
+			userAgent:         "darwin user agent",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-darwin-x86.tar.gz",
+		},
+		{
+			name:              "linux option",
+			requestPath:       "/username/repo?os=linux",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-linux-x86.tar.gz",
+		},
+		{
+			name:              "linux user-agent",
+			requestPath:       "/username/repo",
+			userAgent:         "linux user agent",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-linux-x86.tar.gz",
+		},
+		{
+			name:              "windows option",
+			requestPath:       "/username/repo?os=windows",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-windows-x86.tar.gz",
+		},
+		{
+			name:              "windows user-agent",
+			requestPath:       "/username/repo",
+			userAgent:         "windows user agent",
+			githubAPIResponse: defaultGithubAPIResponse,
+			wantRedirect:      "http://localhost/some-file-windows-x86.tar.gz",
+		},
+	}
+
+	for _, tc := range cases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			wantRequestURL := "/repos/username/repo/releases"
+
+			// Setup fake GitHub server.
+			githubServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+				if req.URL.String() != wantRequestURL {
+					t.Errorf("unexpected request URL. got: %v, want: %v", req.URL.String(), wantRequestURL)
+					w.WriteHeader(http.StatusBadRequest)
+					return
+				}
+				w.Write(tc.githubAPIResponse)
+			}))
+			defer githubServer.Close()
+			tempSetGithubAPIBase(t, githubServer.URL)
+
+			// Setup test getbin server to wrap the Download handler.
+			router := httprouter.New()
+			router.GET("/:username/:repo", Download)
+			server := httptest.NewServer(router)
+			defer server.Close()
+
+			// Make test request and client to getbin.
+			req, err := http.NewRequest(http.MethodGet, server.URL+tc.requestPath, nil)
+			if err != nil {
+				t.Fatalf("unable to make GET request to getbin server: %v", err)
+			}
+			req.Header.Set("User-Agent", tc.userAgent)
+
+			cl := &http.Client{CheckRedirect: func(req *http.Request, via []*http.Request) error {
+				// Need to return an error to stop the client from auto
+				// redirecting, since we want to inspect the redirect.
+				return errStopRedirect
+			}}
+
+			res, err := cl.Do(req)
+			if !errors.Is(err, errStopRedirect) {
+				t.Errorf("Unexpected error when making getbin request: %v", err)
+			}
+
+			if res.StatusCode != http.StatusMovedPermanently {
+				t.Errorf("unexpected StatusCode in response. got: %v, want: %v", res.StatusCode, http.StatusMovedPermanently)
+			}
+			if got := res.Header.Get("Location"); got != tc.wantRedirect {
+				t.Errorf("unexpected redirect in response. got: %v, want: %v", got, tc.wantRedirect)
+			}
+		})
+	}
+}
+
+func tempSetGithubAPIBase(t *testing.T, newAPIBase string) {
+	origVal := releases.GithubAPIBase
+	releases.GithubAPIBase = newAPIBase
+	t.Cleanup(func() {
+		releases.GithubAPIBase = origVal
+	})
+}

main.go

@@ -6,7 +6,7 @@ import (
 	"net/http"
 
 	"github.com/julienschmidt/httprouter"
-	"github.com/suyashkumar/bin/handlers"
+	"github.com/suyashkumar/getbin/handlers"
 	"golang.org/x/crypto/acme/autocert"
 )
 

releases/releases.go

@@ -7,8 +7,9 @@ import (
 	"net/http"
 )
 
-// GithubAPIBase represents the base url for the GitHub API
-const GithubAPIBase = "https://api.github.com"
+// GithubAPIBase represents the base url for the GitHub API. This can be
+// changed, primarily for test purposes.
+var GithubAPIBase = "https://api.github.com"
 
 // Content type constants
 const (