refactor `update` command to use git diff instead of parsing `pull` output

This fixes reporting of which formulae changed in git versions where `pull`
output is not compatible.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>

2 files changed, 78 insertions, 76 deletions

diff --git a/Library/Homebrew/test/fixtures/updater_fixture.yaml b/Library/Homebrew/test/fixtures/updater_fixture.yaml
index 55e9d0f40..b3dd14d23 100644
--- a/Library/Homebrew/test/fixtures/updater_fixture.yaml
+++ b/Library/Homebrew/test/fixtures/updater_fixture.yaml
@@ -1,53 +1,26 @@
-update_git_pull_output_without_formulae_changes: |
-  remote: counting objects: 58, done.
-  remote: Compressing objects: 100% (35/35), done.
-  remote: Total 39 (delta 20), reused 0 (delta 0)
-  Unpacking objects: 100% (39/39), done.
-  From git://github.com/mxcl/homebrew
-   * branch            master -> FETCH_HEAD
-  Updating 14ef7f9..f414bc8
-  Fast forward
-   Library/Homebrew/ARGV+yeast.rb                |   35 ++--
-   Library/Homebrew/beer_events.rb               |  181 +++++++++++++
-   Library/Homebrew/hardware.rb                  |   71 ++++++
-   Library/Homebrew/hw.model.c                   |   17 --
-   README                                        |  337 +++++++++++++------------
-   bin/brew                                      |  137 ++++++++---
-   40 files changed, 1107 insertions(+), 426 deletions(-)
-   create mode 100644 Library/Homebrew/beer_events.rb
-   create mode 100644 Library/Homebrew/hardware.rb
-   delete mode 100644 Library/Homebrew/hw.model.c
-   delete mode 100644 Library/Homebrew/hw.model.rb
-update_git_pull_output_with_formulae_changes: |
-  remote: counting objects: 58, done.
-  remote: Compressing objects: 100% (35/35), done.
-  remote: Total 39 (delta 20), reused 0 (delta 0)
-  Unpacking objects: 100% (39/39), done.
-  From git://github.com/mxcl/homebrew
-   * branch            master -> FETCH_HEAD
-  Updating 14ef7f9..f414bc8
-  Fast forward
-   Library/Contributions/brew_bash_completion.sh |    6 +-
-   Library/Formula/antiword.rb                   |   13 +
-   Library/Formula/bash-completion.rb            |   25 ++
-   Library/Formula/xar.rb                        |   19 ++
-   Library/Formula/yajl.rb                       |    2 +-
-   Library/Homebrew/ARGV+yeast.rb                |   35 ++--
-   Library/Homebrew/beer_events.rb               |  181 +++++++++++++
-   Library/Homebrew/hardware.rb                  |   71 ++++++
-   Library/Homebrew/hw.model.c                   |   17 --
-   Library/Homebrew/pathname+yeast.rb            |   28 ++-
-   Library/Homebrew/unittest.rb                  |  106 ++++++++-
-   Library/Homebrew/utils.rb                     |   36 ++-
-   README                                        |  337 +++++++++++++------------
-   bin/brew                                      |  137 ++++++++---
-   40 files changed, 1107 insertions(+), 426 deletions(-)
-   create mode 100644 Library/Formula/antiword.rb
-   create mode 100644 Library/Formula/bash-completion.rb
-   create mode 100644 Library/Formula/ddrescue.rb
-   create mode 100644 Library/Formula/dict.rb
-   create mode 100644 Library/Formula/lua.rb
-   create mode 100644 Library/Homebrew/beer_events.rb
-   create mode 100644 Library/Homebrew/hardware.rb
-   delete mode 100644 Library/Homebrew/hw.model.c
-   delete mode 100644 Library/Homebrew/hw.model.rb
+update_git_diff_output_without_formulae_changes: |
+  M       Library/Homebrew/ARGV+yeast.rb
+  A       Library/Homebrew/beer_events.rb
+  A       Library/Homebrew/hardware.rb
+  D       Library/Homebrew/hw.model.c
+  M       README
+  M       bin/brew
+update_git_diff_output_with_formulae_changes: |
+  M       Library/Contributions/brew_bash_completion.sh
+  A       Library/Formula/antiword.rb
+  A       Library/Formula/bash-completion.rb
+  M       Library/Formula/xar.rb
+  M       Library/Formula/yajl.rb
+  M       Library/Homebrew/ARGV+yeast.rb
+  M       Library/Homebrew/pathname+yeast.rb
+  M       Library/Homebrew/unittest.rb
+  M       Library/Homebrew/utils.rb
+  M       README
+  M       bin/brew
+  A       Library/Formula/ddrescue.rb
+  A       Library/Formula/dict.rb
+  A       Library/Formula/lua.rb
+  A       Library/Homebrew/beer_events.rb
+  A       Library/Homebrew/hardware.rb
+  D       Library/Homebrew/hw.model.c
+  D       Library/Homebrew/hw.model.rb
diff --git a/Library/Homebrew/test/test_updater.rb b/Library/Homebrew/test/test_updater.rb
index 348658d25..b5247f684 100644
--- a/Library/Homebrew/test/test_updater.rb
+++ b/Library/Homebrew/test/test_updater.rb
@@ -11,15 +11,23 @@ require 'utils'
 require 'cmd/update'
 
 class RefreshBrewMock < RefreshBrew
-  def in_prefix_expect(expect, returns = '')
-    @expect ||= {}
-    @expect[expect] = returns
+  def git_repo?
+    @git_repo
+  end
+  attr_writer :git_repo
+
+  def in_prefix_expect(cmd, output = '')
+    @outputs  ||= Hash.new { |h,k| h[k] = [] }
+    @expected ||= []
+    @expected << cmd
+    @outputs[cmd] << output
   end
   
   def `(cmd)
-    if Dir.pwd == HOMEBREW_PREFIX.to_s and @expect.has_key?(cmd)
-      (@called ||= []) << cmd
-      @expect[cmd]
+    if Dir.pwd == HOMEBREW_PREFIX.to_s and @expected.include?(cmd) and !@outputs[cmd].empty?
+      @called ||= []
+      @called << cmd
+      @outputs[cmd].shift
     else
       raise "#{inspect} Unexpectedly called backticks in pwd `#{HOMEBREW_PREFIX}' and command `#{cmd}'"
     end
@@ -28,7 +36,7 @@ class RefreshBrewMock < RefreshBrew
   alias safe_system `
   
   def expectations_met?
-    @expect.keys.sort == @called.sort
+    @expected == @called
   end
   
   def inspect
@@ -54,11 +62,30 @@ class UpdaterTests < Test::Unit::TestCase
     @fixture_data
   end
 
+  def test_init_homebrew
+    outside_prefix do
+      updater = RefreshBrewMock.new
+      updater.git_repo = false
+      updater.in_prefix_expect("git init")
+      updater.in_prefix_expect("git pull #{RefreshBrewMock::REPOSITORY_URL} master")
+      updater.in_prefix_expect("git rev-parse HEAD", "1234abcd")
+      
+      assert_equal false, updater.update_from_masterbrew!
+      assert updater.expectations_met?
+      assert updater.updated_formulae.empty?
+      assert updater.added_formulae.empty?
+    end
+  end
+
   def test_update_homebrew_without_any_changes
     outside_prefix do
       updater = RefreshBrewMock.new
-      updater.in_prefix_expect(RefreshBrew::INIT_COMMAND)
-      updater.in_prefix_expect(RefreshBrew::UPDATE_COMMAND, "Already up-to-date.\n")
+      updater.git_repo = true
+      updater.in_prefix_expect("git checkout -q master")
+      updater.in_prefix_expect("git rev-parse HEAD", "1234abcd")
+      updater.in_prefix_expect("git pull #{RefreshBrewMock::REPOSITORY_URL} master")
+      updater.in_prefix_expect("git rev-parse HEAD", "3456cdef")
+      updater.in_prefix_expect("git diff-tree -r --name-status -z 1234abcd 3456cdef", "")
       
       assert_equal false, updater.update_from_masterbrew!
       assert updater.expectations_met?
@@ -70,9 +97,14 @@ class UpdaterTests < Test::Unit::TestCase
   def test_update_homebrew_without_formulae_changes
     outside_prefix do
       updater = RefreshBrewMock.new
-      updater.in_prefix_expect(RefreshBrew::INIT_COMMAND)
-      output = fixture('update_git_pull_output_without_formulae_changes')
-      updater.in_prefix_expect(RefreshBrew::UPDATE_COMMAND, output)
+      updater.git_repo = true
+      diff_output = fixture('update_git_diff_output_without_formulae_changes')
+
+      updater.in_prefix_expect("git checkout -q master")
+      updater.in_prefix_expect("git rev-parse HEAD", "1234abcd")
+      updater.in_prefix_expect("git pull #{RefreshBrewMock::REPOSITORY_URL} master")
+      updater.in_prefix_expect("git rev-parse HEAD", "3456cdef")
+      updater.in_prefix_expect("git diff-tree -r --name-status -z 1234abcd 3456cdef", diff_output.gsub(/\s+/, "\0"))
       
       assert_equal true, updater.update_from_masterbrew!
       assert !updater.pending_formulae_changes?
@@ -84,9 +116,14 @@ class UpdaterTests < Test::Unit::TestCase
   def test_update_homebrew_with_formulae_changes
     outside_prefix do
       updater = RefreshBrewMock.new
-      updater.in_prefix_expect(RefreshBrew::INIT_COMMAND)
-      output = fixture('update_git_pull_output_with_formulae_changes')
-      updater.in_prefix_expect(RefreshBrew::UPDATE_COMMAND, output)
+      updater.git_repo = true
+      diff_output = fixture('update_git_diff_output_with_formulae_changes')
+
+      updater.in_prefix_expect("git checkout -q master")
+      updater.in_prefix_expect("git rev-parse HEAD", "1234abcd")
+      updater.in_prefix_expect("git pull #{RefreshBrewMock::REPOSITORY_URL} master")
+      updater.in_prefix_expect("git rev-parse HEAD", "3456cdef")
+      updater.in_prefix_expect("git diff-tree -r --name-status -z 1234abcd 3456cdef", diff_output.gsub(/\s+/, "\0"))
       
       assert_equal true, updater.update_from_masterbrew!
       assert updater.pending_formulae_changes?
@@ -94,12 +131,4 @@ class UpdaterTests < Test::Unit::TestCase
       assert_equal %w{ antiword bash-completion ddrescue dict lua }, updater.added_formulae
     end
   end
-  
-  def test_updater_returns_current_revision
-    outside_prefix do
-      updater = RefreshBrewMock.new
-      updater.in_prefix_expect(RefreshBrew::REVISION_COMMAND, 'the-revision-hash')
-      assert_equal 'the-revision-hash', updater.current_revision
-    end
-  end
 end