From 98abf2937e42d560f0a8ba3c9e5bd5351c5316e6 Mon Sep 17 00:00:00 2001
From: Shenghou Ma <minux@golang.org>
Date: Thu, 26 Nov 2015 17:45:09 -0500
Subject: [PATCH] cmd/cover: allow part selection to be retained across page
 refreshes

Usually, you are primarily interested to see the coverage of a particular
file (e.g. when you're changing tests that affects a given source file),
it is very valuable if you can just refresh the page and immediately see
changes to the part you're already looking at (without selecting from the
selector again.)

Change-Id: I615207c9be6713f436e444771134fceaf4600ff3
Reviewed-on: https://go-review.googlesource.com/17238
Run-TryBot: Minux Ma <minux@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
---
 src/cmd/cover/html.go | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/src/cmd/cover/html.go b/src/cmd/cover/html.go
index bb0a495ae7..d0ac4476ba 100644
--- a/src/cmd/cover/html.go
+++ b/src/cmd/cover/html.go
@@ -258,21 +258,35 @@ const tmplHTML = `
 		</div>
 		<div id="content">
 		{{range $i, $f := .Files}}
-		<pre class="file" id="file{{$i}}" {{if $i}}style="display: none"{{end}}>{{$f.Body}}</pre>
+		<pre class="file" id="file{{$i}}" style="display: none">{{$f.Body}}</pre>
 		{{end}}
 		</div>
 	</body>
 	<script>
 	(function() {
 		var files = document.getElementById('files');
-		var visible = document.getElementById('file0');
+		var visible;
 		files.addEventListener('change', onChange, false);
-		function onChange() {
-			visible.style.display = 'none';
-			visible = document.getElementById(files.value);
+		function select(part) {
+			if (visible)
+				visible.style.display = 'none';
+			visible = document.getElementById(part);
+			if (!visible)
+				return;
+			files.value = part;
 			visible.style.display = 'block';
+			location.hash = part;
+		}
+		function onChange() {
+			select(files.value);
 			window.scrollTo(0, 0);
 		}
+		if (location.hash != "") {
+			select(location.hash.substr(1));
+		}
+		if (!visible) {
+			select("file0");
+		}
 	})();
 	</script>
 </html>
-- 
2.48.1