From 2a3f4ea21af08f759eb5089122e2b9f70ab6b1e2 Mon Sep 17 00:00:00 2001
From: Justin Hawkins <justin@hawkins.id.au>
Date: Mon, 11 Oct 2021 20:25:53 +1030
Subject: [PATCH] Add the ability to mock the http client and a test.

---
 upload/upload.go      | 27 +++++++++++++++++++------
 upload/upload_test.go | 47 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 6 deletions(-)
 create mode 100644 upload/upload_test.go

diff --git a/upload/upload.go b/upload/upload.go
index 1a34b25..bf7d924 100644
--- a/upload/upload.go
+++ b/upload/upload.go
@@ -15,6 +15,7 @@ import (
 	"os"
 	"path/filepath"
 	"time"
+	"errors"
 
 	"github.com/fogleman/gg"
 	"github.com/tardisx/discord-auto-upload/config"
@@ -22,6 +23,10 @@ import (
 	"golang.org/x/image/font/inconsolata"
 )
 
+type HTTPClient interface {
+	Do(req *http.Request) (*http.Response, error)
+}
+
 type Uploader struct {
 	Uploads []*Upload `json:"uploads"`
 }
@@ -43,6 +48,8 @@ type Upload struct {
 
 	Width  int `json:"width"`
 	Height int `json:"height"`
+
+	Client HTTPClient
 }
 
 func NewUploader() *Uploader {
@@ -73,10 +80,10 @@ func (u *Uploader) Upload() {
 	}
 }
 
-func (u *Upload) processUpload() {
+func (u *Upload) processUpload() error {
 	if u.webhookURL == "" {
 		daulog.SendLog("WebHookURL is not configured - cannot upload!", daulog.LogTypeError)
-		return
+		return errors.New("webhook url not configured")
 	}
 
 	if u.watermark {
@@ -112,11 +119,18 @@ func (u *Upload) processUpload() {
 
 		request, err := newfileUploadRequest(u.webhookURL, extraParams, "file", u.filenameToUpload)
 		if err != nil {
-			log.Fatal(err)
+			log.Printf("error creating upload request: %s", err)
+			return fmt.Errorf("could not create upload request: %s", err)
 		}
 		start := time.Now()
-		client := &http.Client{Timeout: time.Second * 30}
-		resp, err := client.Do(request)
+
+		if u.Client == nil {
+	          // if no client was specified (a unit test) then create
+		  // a default one
+		  u.Client = &http.Client{Timeout: time.Second * 30}
+		}
+
+		resp, err := u.Client.Do(request)
 		if err != nil {
 			log.Print("Error performing request:", err)
 			retriesRemaining--
@@ -190,12 +204,13 @@ func (u *Upload) processUpload() {
 	if retriesRemaining == 0 {
 		daulog.SendLog("Failed to upload, even after all retries", daulog.LogTypeError)
 	}
+	return nil
 }
 
 func newfileUploadRequest(uri string, params map[string]string, paramName, path string) (*http.Request, error) {
 	file, err := os.Open(path)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("could not open file '%s': %s", path, err)
 	}
 	defer file.Close()
 
diff --git a/upload/upload_test.go b/upload/upload_test.go
new file mode 100644
index 0000000..055744e
--- /dev/null
+++ b/upload/upload_test.go
@@ -0,0 +1,47 @@
+package upload
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"testing"
+	"os"
+	// 	"github.com/tardisx/discord-auto-upload/config"
+)
+
+// https://www.thegreatcodeadventure.com/mocking-http-requests-in-golang/
+type MockClient struct {
+	DoFunc func(req *http.Request) (*http.Response, error)
+}
+
+func (m *MockClient) Do(req *http.Request) (*http.Response, error) {
+	return m.DoFunc(req)
+}
+
+func DoGoodUpload(req *http.Request) (*http.Response, error) {
+	r := ioutil.NopCloser(bytes.NewReader([]byte(`{"id": "123456789012345678", "type": 0, "content": "", "channel_id": "849615269706203171", "author": {"bot": true, "id": "849615314274484224", "username": "abcdedf", "avatar": null, "discriminator": "0000"}, "attachments": [{"id": "851092588332449812", "filename": "dau480457962.png", "size": 859505, "url": "https://cdn.discordapp.com/attachments/849615269706203171/851092588332449812/dau480457962.png", "proxy_url": "https://media.discordapp.net/attachments/849615269706203171/851092588332449812/dau480457962.png", "width": 640, "height": 640, "content_type": "image/png"}], "embeds": [], "mentions": [], "mention_roles": [], "pinned": false, "mention_everyone": false, "tts": false, "timestamp": "2021-06-06T13:38:05.660000+00:00", "edited_timestamp": null, "flags": 0, "components": [], "webhook_id": "123456789012345678"}`)))
+	return &http.Response{
+		StatusCode: 200,
+		Body:       r,
+	}, nil
+}
+
+func TestSuccessfulUpload(t *testing.T) {
+	// create temporary file, processUpload requires that it exists, even though
+	// we will not really be uploading it here
+	f, _ := os.CreateTemp("", "dautest-upload-*")
+	defer os.Remove(f.Name())
+	u := Upload{webhookURL: "https://127.0.0.1/", originalFilename: f.Name()}
+	u.Client = &MockClient{DoFunc: DoGoodUpload}
+	err := u.processUpload()
+	if err != nil {
+		t.Errorf("error occured: %s", err)
+	}
+	if u.Width != 640 || u.Height != 640 {
+		t.Error("dimensions wrong")
+	}
+	if u.Url != "https://cdn.discordapp.com/attachments/849615269706203171/851092588332449812/dau480457962.png" {
+		t.Error("URL wrong")
+	}
+
+}