[PATCH] git-prompt.sh: Option to hide prompt for ignored pwd

[Jess Austin <jess.austin@gmail.com>]

Optionally set __git_ps1 to display nothing when present working
directory is ignored, triggered by the new environmental variable
GIT_PS1_HIDE_IF_PWD_IGNORED. This environmental variable may be
overridden on any repository by setting bash.hideIfPwdIgnored to
"false". In the absence of GIT_PS1_HIDE_IF_PWD_IGNORED this change
has no effect.

Many people manage e.g. dotfiles in their home directory with git.
This causes the prompt generated by __git_ps1 to refer to that "top
level" repo while working in any descendant directory. That can be
distracting, so this patch helps one shut off that noise.

Signed-off-by: Jess Austin <jess.austin@gmail.com>
---
On Tue, Oct 14, 2014 at 2:08 PM, Richard Hansen <rhansen@bbn.com> wrote:
> On 2014-10-14 14:47, Johannes Sixt wrote:
>> Ahem, no. Please do not punish users who are not interested in the new
>> feature with two new processes every time __git_ps() is run. Think of
>> Windows where fork() is really, *really* expensive.
> Regardless, it would be nice if the behavior matched the other bash.*
> variables (only check the bash.* variable if the corresponding
> environment variable is set, and default to true).  The following should
> fix it:
>
>     if [ -n "${GIT_PS1_HIDE_ON_IGNORED_PWD}" ] &&
>        [ "$(git config --bool bash.hideOnIgnoredPwd)" != "false" ] &&
>        [ "$(git check-ignore .)" ]
>     then
Thanks for helping me understand this! I think I have it correct now.


On Tue, Oct 14, 2014 at 2:21 PM, Richard Hansen <rhansen@bbn.com> wrote:
> I do prefer the new names.  They are long, but how often will someone
> have to type it?  In this case it's better to be descriptive than to be
> short.  (I wonder if adding two letters would improve readability
> further:  GIT_PS1_HIDE_WHEN_PWD_IGNORED and bash.hideWhenPwdIgnored.)

We got those two letters back with GIT_PS1_HIDE_IF_PWD_IGNORED and
bash.hideIfPwdIgnored.

> To avoid scaring people who might not want this feature enabled, I
> recommend changing the subject line to something like this:
>
>     git-prompt.sh: Option to hide prompt for ignored pwd

Good idea!


 contrib/completion/git-prompt.sh | 12 ++++++++++++
 t/t9903-bash-prompt.sh           | 42 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index c5473dc..151218b 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -84,6 +84,11 @@
 # GIT_PS1_SHOWCOLORHINTS to a nonempty value. The colors are based on
 # the colored output of "git status -sb" and are available only when
 # using __git_ps1 for PROMPT_COMMAND or precmd.
+#
+# If you would like __git_ps1 to do nothing in the case when the current
+# directory is set up to be ignored by git, then set
+# GIT_PS1_HIDE_IF_PWD_IGNORED to a nonempty value. Override this on the
+# repository level by setting bash.hideIfPwdIgnored to "false".
 
 # check whether printf supports -v
 __git_printf_supports_v=
@@ -501,6 +506,13 @@ __git_ps1 ()
 	local f="$w$i$s$u"
 	local gitstring="$c$b${f:+$z$f}$r$p"
 
+	if [ -n "${GIT_PS1_HIDE_IF_PWD_IGNORED}" ] &&
+	   [ "$(git config --bool bash.hideIfPwdIgnored)" != "false" ] &&
+	   git check-ignore -q .
+	then
+		printf_format=""
+	fi
+
 	if [ $pcmode = yes ]; then
 		if [ "${__git_printf_supports_v-}" != yes ]; then
 			gitstring=$(printf -- "$printf_format" "$gitstring")
diff --git a/t/t9903-bash-prompt.sh b/t/t9903-bash-prompt.sh
index 9150984..88a75cf 100755
--- a/t/t9903-bash-prompt.sh
+++ b/t/t9903-bash-prompt.sh
@@ -35,6 +35,8 @@ test_expect_success 'setup for prompt tests' '
 	git commit -m "another b2" file &&
 	echo 000 >file &&
 	git commit -m "yet another b2" file &&
+	mkdir ignored_dir &&
+	echo "ignored_dir/" >> .gitignore &&
 	git checkout master
 '
 
@@ -588,4 +590,44 @@ test_expect_success 'prompt - zsh color pc mode' '
 	test_cmp expected "$actual"
 '
 
+test_expect_success 'prompt - hide if pwd ignored - shell variable unset with config disabled' '
+	printf " (master)" >expected &&
+	test_config bash.hideIfPwdIgnored false &&
+	(
+		cd ignored_dir &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'prompt - hide if pwd ignored - shell variable unset with config unset' '
+	printf " (master)" >expected &&
+	(
+		cd ignored_dir &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'prompt - hide if pwd ignored - shell variable set with config disabled' '
+	printf " (master)" >expected &&
+	test_config bash.hideIfPwdIgnored false &&
+	(
+		cd ignored_dir &&
+		GIT_PS1_HIDE_IF_PWD_IGNORED=y &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
+test_expect_success 'prompt - hide if pwd ignored - shell variable set with config unset' '
+	printf "" >expected &&
+	(
+		cd ignored_dir &&
+		GIT_PS1_HIDE_IF_PWD_IGNORED=y &&
+		__git_ps1 >"$actual"
+	) &&
+	test_cmp expected "$actual"
+'
+
 test_done
-- 
1.9.1