From 6f3897ce2cbd22f41f5dd4f3ba9db71ac58fcede Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Fri, 1 Jul 2016 11:30:09 +0100
Subject: [PATCH] b2: implement --b2-test-mode to set `X-Bz-Test-Mode` header
 #420

---
 b2/b2.go           |  8 ++++++++
 docs/content/b2.md | 17 +++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/b2/b2.go b/b2/b2.go
index 801aa2492..b4457c42c 100644
--- a/b2/b2.go
+++ b/b2/b2.go
@@ -39,6 +39,7 @@ const (
 	maxSleep        = 2 * time.Second
 	decayConstant   = 2 // bigger for slower decay, exponential
 	maxParts        = 10000
+	testModeHeader  = "X-Bz-Test-Mode"
 )
 
 // Globals
@@ -49,6 +50,7 @@ var (
 	errorAuthTokenExpired       = errors.New("b2 auth token expired")
 	errorUploadTokenExpired     = errors.New("b2 upload token expired")
 	errorUploadPartTokenExpired = errors.New("b2 upload part token expired")
+	b2TestMode                  = pflag.StringP("b2-test-mode", "", "", "A flag string for X-Bz-Test-Mode header.")
 )
 
 // Register with Fs
@@ -224,6 +226,12 @@ func NewFs(name, root string) (fs.Fs, error) {
 		pacer:        pacer.New().SetMinSleep(minSleep).SetMaxSleep(maxSleep).SetDecayConstant(decayConstant),
 		uploadTokens: make(chan struct{}, fs.Config.Transfers),
 	}
+	// Set the test flag if required
+	if *b2TestMode != "" {
+		testMode := strings.TrimSpace(*b2TestMode)
+		f.srv.SetHeader(testModeHeader, testMode)
+		fs.Debug(f, "Setting test header \"%s: %s\"", testModeHeader, testMode)
+	}
 	// Fill up the upload tokens
 	for i := 0; i < fs.Config.Transfers; i++ {
 		f.returnUploadToken()
diff --git a/docs/content/b2.md b/docs/content/b2.md
index 870712f1b..e08ac4898 100644
--- a/docs/content/b2.md
+++ b/docs/content/b2.md
@@ -151,8 +151,17 @@ Cutoff for switching to chunked upload (default 4.657GiB ==
 `--b2-chunk-size`. The default value is the largest file which can be
 uploaded without chunks.
 
-### API ###
+#### --b2-test-mode=FLAG ####
 
-Here are [some notes I made on the backblaze
-API](https://gist.github.com/ncw/166dabf352b399f1cc1c) while
-integrating it with rclone.
+This is for debugging purposes only.
+
+Setting FLAG to one of the strings below will cause b2 to return
+specific errors for debugging purposes.
+
+  * `fail_some_uploads`
+  * `expire_some_account_authorization_tokens`
+  * `force_cap_exceeded`
+
+These will be set in the `X-Bz-Test-Mode` header which is documented
+in the [b2 integrations
+checklist](https://www.backblaze.com/b2/docs/integration_checklist.html).