From 4e1c51cb894ec1c8bea6da4062ba193ae4779d45 Mon Sep 17 00:00:00 2001
From: Michael Toy <michael@toyland.org>
Date: Mon, 20 Mar 2017 13:50:37 -0700
Subject: [PATCH] Make gem self versioning

---
 nullgem.gemspec | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/nullgem.gemspec b/nullgem.gemspec
index 3388824..0f49611 100644
--- a/nullgem.gemspec
+++ b/nullgem.gemspec
@@ -1,7 +1,18 @@
 Gem::Specification.new do |gem|
   gem.name          = "nullgem"
-  gem.version       = '0.0.0'
-  gem.date          = '2001-01-01'
+  gem.version     = begin
+    head_sha          = %x{git rev-parse HEAD}.strip
+    tag_version       = %x{git name-rev --tags --name-only #{head_sha}}.strip
+    untracked_files   = (%x{git ls-files --others --exclude-standard}.strip != '')
+    _diff_status_only =  %x{git diff --quiet --exit-code HEAD}
+    head_diff = ($?.exitstatus != 0)
+
+    version = (tag_version =~ /^\d+\.\d+\.\d+$/) ? tag_version : "0.0.0.#{head_sha[0..7]}"
+    dev_tag = (untracked_files || head_diff) ? '-dev' : ''
+
+    version + dev_tag
+  end
+  gem.date          = '2012-03-04'
   gem.authors       = ["Michael Toy"]
   gem.email         = ["michael@toyland.org"]
   gem.description   = %q{A gem which does nothing, for testing}