diff --git a/tests/test-diff-ignore-whitespace.out b/tests/test-diff-ignore-whitespace.out
deleted file mode 100644
--- a/tests/test-diff-ignore-whitespace.out
+++ /dev/null
@@ -1,281 +0,0 @@
-adding foo
->>> two diffs showing three added lines <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
-+
- hello world
-+
- goodbye world
-+
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
-+
- hello world
-+
- goodbye world
-+
->>> no diffs <<<
-hg diff -B
-hg diff -Bb
->>> four diffs showing added space first on the first line <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+	 hello world
- goodbye world
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+	 hello world
- goodbye world
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+	 hello world
- goodbye world
-hg diff -Bb
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+	 hello world
- goodbye world
->>> two diffs showing space appended to the first line <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+hello world	 
- goodbye world
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+hello world	 
- goodbye world
->>> no diffs <<<
-hg diff -b
-hg diff -Bb
->>> four diffs showing space inserted into "goodbye" <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+good bye world
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+good bye world
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+good bye world
-hg diff -Bb
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+good bye world
->>> two diffs showing changed whitespace amount in the last line <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+goodbye		  	world
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
- hello world
--goodbye world
-+goodbye		  	world
->>> no diffs <<<
-hg diff -b
-hg diff -Bb
->>> four diffs showing added blank line w/horizontal space <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
- hello world
-+ 	
- goodbye world
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
- hello world
-+ 	
- goodbye world
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
- hello world
-+ 	
- goodbye world
-hg diff -Bb
->>> three diffs showing added blank line w/other space <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
--hello world
--goodbye world
-+hello  world
-+ 	
-+goodbye world 
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
--hello world
--goodbye world
-+hello  world
-+ 	
-+goodbye world 
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,3 @@
- hello world
-+ 	
- goodbye world
-hg diff -Bb
->>> four diffs showing changed whitespace <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
--goodbye world
-+helloworld
-+goodbye	world 
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
--goodbye world
-+helloworld
-+goodbye	world 
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+helloworld
- goodbye world
-hg diff -Bb
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,2 @@
--hello world
-+helloworld
- goodbye world
-hg diff -w
->>> five diffs showing changed whitespace <<<
-hg diff
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
--hello world
--goodbye world
-+helloworld
-+
-+
-+
-+goodbye	world 
-hg diff -B
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
--hello world
--goodbye world
-+helloworld
-+
-+
-+
-+goodbye	world 
-hg diff -b
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
--hello world
-+helloworld
-+
-+
-+
- goodbye world
-hg diff -Bb
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
--hello world
-+helloworld
-+
-+
-+
- goodbye world
-hg diff -w
-diff -r 540c40a65b78 foo
---- a/foo
-+++ b/foo
-@@ -1,2 +1,5 @@
- hello world
-+
-+
-+
- goodbye world
-hg diff -wB
diff --git a/tests/test-diff-ignore-whitespace b/tests/test-diff-ignore-whitespace.t
old mode 100755
new mode 100644
rename from tests/test-diff-ignore-whitespace
rename to tests/test-diff-ignore-whitespace.t
--- a/tests/test-diff-ignore-whitespace
+++ b/tests/test-diff-ignore-whitespace.t
@@ -1,121 +1,392 @@
-#!/bin/sh
+GNU diff is the reference for all of these results.
+
+Prepare tests:
+
+  $ echo '[alias]' >> $HGRCPATH
+  $ echo 'ndiff = diff --nodates' >> $HGRCPATH
 
-# GNU diff is the reference for all of these results.
+  $ hg init
+  $ printf 'hello world\ngoodbye world\n' >foo
+  $ hg ci -Amfoo -ufoo
+  adding foo
+
+
+Test added blank lines:
+
+  $ printf '\nhello world\n\ngoodbye world\n\n' >foo
+
+>>> two diffs showing three added lines <<<
 
-hgdiff() {
-    echo hg diff $@
-    hg diff --nodates "$@"
-}
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  +
+   hello world
+  +
+   goodbye world
+  +
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  +
+   hello world
+  +
+   goodbye world
+  +
 
-test_added_blank_lines() {
-    printf '\nhello world\n\ngoodbye world\n\n' >foo
+>>> no diffs <<<
+
+  $ hg ndiff -B
+  $ hg ndiff -Bb
+
 
-    echo '>>> two diffs showing three added lines <<<'
-    hgdiff
-    hgdiff -b
+Test added horizontal space first on a line():
+
+  $ printf '\t hello world\ngoodbye world\n' >foo
+
+>>> four diffs showing added space first on the first line <<<
+
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +	 hello world
+   goodbye world
+
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +	 hello world
+   goodbye world
 
-    echo '>>> no diffs <<<'
-    hgdiff -B
-    hgdiff -Bb
-}
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +	 hello world
+   goodbye world
 
-test_added_horizontal_space_first_on_a_line() {
-    printf '\t hello world\ngoodbye world\n' >foo
+  $ hg ndiff -Bb
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +	 hello world
+   goodbye world
+
+
+Test added horizontal space last on a line:
+
+  $ printf 'hello world\t \ngoodbye world\n' >foo
+
+>>> two diffs showing space appended to the first line <<<
 
-    echo '>>> four diffs showing added space first on the first line <<<'
-    hgdiff
-    hgdiff -b
-    hgdiff -B
-    hgdiff -Bb
-}
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +hello world	 
+   goodbye world
+
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +hello world	 
+   goodbye world
+
+>>> no diffs <<<
+
+  $ hg ndiff -b
+  $ hg ndiff -Bb
+
 
-test_added_horizontal_space_last_on_a_line() {
-    printf 'hello world\t \ngoodbye world\n' >foo
+Test added horizontal space in the middle of a word:
+
+  $ printf 'hello world\ngood bye world\n' >foo
+
+>>> four diffs showing space inserted into "goodbye" <<<
 
-    echo '>>> two diffs showing space appended to the first line <<<'
-    hgdiff
-    hgdiff -B
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +good bye world
+
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +good bye world
 
-    echo '>>> no diffs <<<'
-    hgdiff -b
-    hgdiff -Bb
-}
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +good bye world
 
-test_added_horizontal_space_in_the_middle_of_a_word() {
-    printf 'hello world\ngood bye world\n' >foo
+  $ hg ndiff -Bb
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +good bye world
+
+
+Test increased horizontal whitespace amount:
+
+  $ printf 'hello world\ngoodbye\t\t  \tworld\n' >foo
+
+>>> two diffs showing changed whitespace amount in the last line <<<
 
-    echo '>>> four diffs showing space inserted into "goodbye" <<<'
-    hgdiff
-    hgdiff -B
-    hgdiff -b
-    hgdiff -Bb
-}
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +goodbye		  	world
 
-test_increased_horizontal_whitespace_amount() {
-    printf 'hello world\ngoodbye\t\t  \tworld\n' >foo
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+   hello world
+  -goodbye world
+  +goodbye		  	world
 
-    echo '>>> two diffs showing changed whitespace amount in the last line <<<'
-    hgdiff
-    hgdiff -B
+>>> no diffs <<<
+
+  $ hg ndiff -b
+  $ hg ndiff -Bb
+
+
+Test added blank line with horizontal whitespace:
+
+  $ printf 'hello world\n \t\ngoodbye world\n' >foo
 
-    echo '>>> no diffs <<<'
-    hgdiff -b
-    hgdiff -Bb
-}
+>>> three diffs showing added blank line with horizontal space <<<
+
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+   hello world
+  + 	
+   goodbye world
+
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+   hello world
+  + 	
+   goodbye world
 
-test_added_blank_line_with_horizontal_whitespace() {
-    printf 'hello world\n \t\ngoodbye world\n' >foo
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+   hello world
+  + 	
+   goodbye world
+
+>>> no diffs <<<
+
+  $ hg ndiff -Bb
+
+
+Test added blank line with other whitespace:
+
+  $ printf 'hello  world\n \t\ngoodbye world \n' >foo
+
+>>> three diffs showing added blank line with other space <<<
 
-    echo '>>> four diffs showing added blank line w/horizontal space <<<'
-    hgdiff
-    hgdiff -B
-    hgdiff -b
-    hgdiff -Bb
-}
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+  -hello world
+  -goodbye world
+  +hello  world
+  + 	
+  +goodbye world 
 
-test_added_blank_line_with_other_whitespace() {
-    printf 'hello  world\n \t\ngoodbye world \n' >foo
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+  -hello world
+  -goodbye world
+  +hello  world
+  + 	
+  +goodbye world 
 
-    echo '>>> three diffs showing added blank line w/other space <<<'
-    hgdiff
-    hgdiff -B
-    hgdiff -b
-    hgdiff -Bb
-}
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,3 @@
+   hello world
+  + 	
+   goodbye world
+
+>>> no diffs <<<
+
+  $ hg ndiff -Bb
+
 
-test_whitespace_changes() {
-    printf 'helloworld\ngoodbye\tworld \n' >foo
+Test whitespace changes:
+
+  $ printf 'helloworld\ngoodbye\tworld \n' >foo
+
+>>> four diffs showing changed whitespace <<<
+
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  -goodbye world
+  +helloworld
+  +goodbye	world 
 
-    echo '>>> four diffs showing changed whitespace <<<'
-    hgdiff
-    hgdiff -B
-    hgdiff -b
-    hgdiff -Bb
-    hgdiff -w
-}
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  -goodbye world
+  +helloworld
+  +goodbye	world 
+
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +helloworld
+   goodbye world
 
-test_whitespace_changes_and_blank_lines() {
-    printf 'helloworld\n\n\n\ngoodbye\tworld \n' >foo
+  $ hg ndiff -Bb
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,2 @@
+  -hello world
+  +helloworld
+   goodbye world
+
+>>> no diffs <<<
+
+  $ hg ndiff -w
+
+
+Test whitespace changes and blank lines:
+
+  $ printf 'helloworld\n\n\n\ngoodbye\tworld \n' >foo
+
+>>> five diffs showing changed whitespace <<<
+
+  $ hg ndiff
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  -hello world
+  -goodbye world
+  +helloworld
+  +
+  +
+  +
+  +goodbye	world 
 
-    echo '>>> five diffs showing changed whitespace <<<'
-    hgdiff
-    hgdiff -B
-    hgdiff -b
-    hgdiff -Bb
-    hgdiff -w
-    hgdiff -wB
-}
+  $ hg ndiff -B
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  -hello world
+  -goodbye world
+  +helloworld
+  +
+  +
+  +
+  +goodbye	world 
+
+  $ hg ndiff -b
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  -hello world
+  +helloworld
+  +
+  +
+  +
+   goodbye world
 
-hg init
-printf 'hello world\ngoodbye world\n' >foo
-hg ci -Amfoo -ufoo
+  $ hg ndiff -Bb
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+  -hello world
+  +helloworld
+  +
+  +
+  +
+   goodbye world
 
-test_added_blank_lines
-test_added_horizontal_space_first_on_a_line
-test_added_horizontal_space_last_on_a_line
-test_added_horizontal_space_in_the_middle_of_a_word
-test_increased_horizontal_whitespace_amount
-test_added_blank_line_with_horizontal_whitespace
-test_added_blank_line_with_other_whitespace
-test_whitespace_changes
-test_whitespace_changes_and_blank_lines
+  $ hg ndiff -w
+  diff -r 540c40a65b78 foo
+  --- a/foo
+  +++ b/foo
+  @@ -1,2 +1,5 @@
+   hello world
+  +
+  +
+  +
+   goodbye world
+
+>>> no diffs <<<
+
+  $ hg ndiff -wB
+