Resolve multiple issues for 1.4

-   Resolve ldiff output issues: Resolves #5 and #6 by adding system-output
    comparison calls to `bin/ldiff` compared against some pre-generated output.
    There is some timestamp manipulation involved with the output comparison,
    as the timestamps are unstable because of the way that git clone works.

-   Resolved a problem with bin/ldiff --context output.

-   Resolved a Numeric/Integer OptParse issue: later versions of Ruby had
    problems working with an `OptParse` option specification of `Numeric`; this
    has been changed to `Integer`.

10 files changed, 116 insertions, 39 deletions

diff --git a/spec/fixtures/aX b/spec/fixtures/aX
new file mode 100644
index 0000000..5765d6a
--- /dev/null
+++ b/spec/fixtures/aX
@@ -0,0 +1 @@
+aX
diff --git a/spec/fixtures/bXaX b/spec/fixtures/bXaX
new file mode 100644
index 0000000..a1c813d
--- /dev/null
+++ b/spec/fixtures/bXaX
@@ -0,0 +1 @@
+bXaX
diff --git a/spec/fixtures/ldiff/output.diff b/spec/fixtures/ldiff/output.diff
new file mode 100644
index 0000000..fa1a347
--- /dev/null
+++ b/spec/fixtures/ldiff/output.diff
@@ -0,0 +1,4 @@
+1c1
+< aX
+---
+> bXaX
diff --git a/spec/fixtures/ldiff/output.diff-c b/spec/fixtures/ldiff/output.diff-c
new file mode 100644
index 0000000..92ea5a2
--- /dev/null
+++ b/spec/fixtures/ldiff/output.diff-c
@@ -0,0 +1,7 @@
+*** spec/fixtures/aX	2019-02-01 22:29:34.000000000 -0500
+--- spec/fixtures/bXaX	2019-02-01 22:29:43.000000000 -0500
+***************
+*** 1 ****
+! aX
+--- 1 ----
+! bXaX
diff --git a/spec/fixtures/ldiff/output.diff-e b/spec/fixtures/ldiff/output.diff-e
new file mode 100644
index 0000000..13e0f7f
--- /dev/null
+++ b/spec/fixtures/ldiff/output.diff-e
@@ -0,0 +1,3 @@
+1c
+bXaX
+.
diff --git a/spec/fixtures/ldiff/output.diff-f b/spec/fixtures/ldiff/output.diff-f
new file mode 100644
index 0000000..77710c7
--- /dev/null
+++ b/spec/fixtures/ldiff/output.diff-f
@@ -0,0 +1,3 @@
+c1
+bXaX
+.
diff --git a/spec/fixtures/ldiff/output.diff-u b/spec/fixtures/ldiff/output.diff-u
new file mode 100644
index 0000000..c4ba30f
--- /dev/null
+++ b/spec/fixtures/ldiff/output.diff-u
@@ -0,0 +1,5 @@
+--- spec/fixtures/aX	2019-02-01 22:29:34.000000000 -0500
++++ spec/fixtures/bXaX	2019-02-01 22:29:43.000000000 -0500
+@@ -1 +1 @@
+-aX
++bXaX
diff --git a/spec/hunk_spec.rb b/spec/hunk_spec.rb
index 5a45072..277f739 100644
--- a/spec/hunk_spec.rb
+++ b/spec/hunk_spec.rb
@@ -13,7 +13,7 @@ if String.method_defined?(:encoding)
 
     it 'produces a unified diff from the two pieces' do
       expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
-        @@ -1,2 +1,2 @@
+        @@ -1 +1 @@
         -Tu avec carté {count} itém has
         +Tu avec carte {count} item has
       EXPECTED
@@ -24,10 +24,10 @@ if String.method_defined?(:encoding)
     it 'produces a context diff from the two pieces' do
       expected = <<-EXPECTED.gsub(/^\s+/, '').encode('UTF-16LE').chomp
         ***************
-        *** 1,2 ****
-        !Tu avec carté {count} itém has
-        --- 1,2 ----
-        !Tu avec carte {count} item has
+        *** 1 ****
+        ! Tu avec carté {count} itém has
+        --- 1 ----
+        ! Tu avec carte {count} item has
       EXPECTED
 
       expect(hunk.diff(:context)).to eq(expected)
@@ -35,7 +35,7 @@ if String.method_defined?(:encoding)
 
     it 'produces an old diff from the two pieces' do
       expected = <<-EXPECTED.gsub(/^ +/, '').encode('UTF-16LE').chomp
-        1,2c1,2
+        1c1
         < Tu avec carté {count} itém has
         ---
         > Tu avec carte {count} item has
@@ -47,7 +47,7 @@ if String.method_defined?(:encoding)
 
     it 'produces a reverse ed diff from the two pieces' do
       expected = <<-EXPECTED.gsub(/^ +/, '').encode('UTF-16LE').chomp
-        c1,2
+        c1
         Tu avec carte {count} item has
         .
 
diff --git a/spec/ldiff_spec.rb b/spec/ldiff_spec.rb
index 113c0dd..6dfea29 100644
--- a/spec/ldiff_spec.rb
+++ b/spec/ldiff_spec.rb
@@ -2,50 +2,71 @@
 
 require 'spec_helper'
 
-describe 'Diff::LCS.diff' do
-  include Diff::LCS::SpecHelper::Matchers
+RSpec.describe 'bin/ldiff' do
+  include CaptureSubprocessIO
 
-  it 'correctly diffs seq1 to seq2' do
-    diff_s1_s2 = Diff::LCS.diff(seq1, seq2)
-    expect(change_diff(correct_forward_diff)).to eq(diff_s1_s2)
+  let(:output_diff) { read_fixture }
+  let(:output_diff_c) { read_fixture('-c') }
+  let(:output_diff_e) { read_fixture('-e') }
+  let(:output_diff_f) { read_fixture('-f') }
+  let(:output_diff_u) { read_fixture('-u') }
+
+  specify do
+    expect(run_ldiff).to eq(output_diff)
   end
 
-  it 'correctly diffs seq2 to seq1' do
-    diff_s2_s1 = Diff::LCS.diff(seq2, seq1)
-    expect(change_diff(correct_backward_diff)).to eq(diff_s2_s1)
+  specify do
+    expect(run_ldiff('-c')).to eq(output_diff_c)
   end
 
-  it 'correctly diffs against an empty sequence' do
-    diff = Diff::LCS.diff(word_sequence, [])
-    correct_diff = [
-      [
-        ['-', 0, 'abcd'],
-        ['-', 1, 'efgh'],
-        ['-', 2, 'ijkl'],
-        ['-', 3, 'mnopqrstuvwxyz']
-      ]
-    ]
+  specify do
+    expect(run_ldiff('-e')).to eq(output_diff_e)
+  end
 
-    expect(change_diff(correct_diff)).to eq(diff)
+  specify do
+    expect(run_ldiff('-f')).to eq(output_diff_f)
+  end
 
-    diff = Diff::LCS.diff([], word_sequence)
-    correct_diff.each do |hunk|
-      hunk.each do |change| change[0] = '+' end
-    end
-    expect(change_diff(correct_diff)).to eq(diff)
+  specify do
+    expect(run_ldiff('-u')).to eq(output_diff_u)
   end
 
-  it "correctly diffs 'xx' and 'xaxb'" do
-    left = 'xx'
-    right = 'xaxb'
-    expect(Diff::LCS.patch(left, Diff::LCS.diff(left, right))).to eq(right)
+  def read_fixture(flag = nil)
+    clean_data(IO.binread("spec/fixtures/ldiff/output.diff#{flag}"), flag)
   end
 
-  it 'returns an empty diff with (hello, hello)' do
-    expect(Diff::LCS.diff(hello, hello)).to eq([])
+  def clean_data(data, flag)
+    case flag
+    when '-c', '-u'
+      clean_output_timestamp(data)
+    else
+      data
+    end
+  end
+
+  def clean_output_timestamp(data)
+    data.gsub(
+      %r{
+        [-*+]{3}
+        \s
+        spec/fixtures/(\w+)
+        \s
+        \d{4}-\d\d-\d\d
+        \s
+        \d\d:\d\d:\d\d(?:\.\d+)
+        \s
+        (?:[-+]\d{4}|Z)
+      }x,
+      '*** spec/fixtures/\1	0000-00-00 00:00:00.000000000 -0000'
+    )
   end
 
-  it 'returns an empty diff with (hello_ary, hello_ary)' do
-    expect(Diff::LCS.diff(hello_ary, hello_ary)).to eq([])
+  def run_ldiff(flag = nil, left: 'aX', right: 'bXaX')
+    stdout, stderr = capture_subprocess_io do
+      system("ruby -Ilib bin/ldiff #{flag} spec/fixtures/#{left} spec/fixtures/#{right}")
+    end
+    expect(stderr).to be_empty
+    expect(stdout).not_to be_empty
+    clean_data(stdout, flag)
   end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 4899c49..e566d0e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -40,6 +40,38 @@ parent = path.parent
 
 $:.unshift parent.join('lib')
 
+module CaptureSubprocessIO
+  def _synchronize
+    yield
+  end
+
+  def capture_subprocess_io
+    _synchronize do
+      begin
+        require 'tempfile'
+
+        captured_stdout, captured_stderr = Tempfile.new('out'), Tempfile.new('err')
+
+        orig_stdout, orig_stderr = $stdout.dup, $stderr.dup
+        $stdout.reopen captured_stdout
+        $stderr.reopen captured_stderr
+
+        yield
+
+        $stdout.rewind
+        $stderr.rewind
+
+        return captured_stdout.read, captured_stderr.read
+      ensure
+        captured_stdout.unlink
+        captured_stderr.unlink
+        $stdout.reopen orig_stdout
+        $stderr.reopen orig_stderr
+      end
+    end
+  end
+end
+
 require 'diff-lcs'
 
 module Diff::LCS::SpecHelper