tests/test-diff-ignore-whitespace

use 'x is None' instead of 'x == None'

The built-in None object is a singleton and it is therefore safe to
compare memory addresses with is. It is also faster, how much depends
on the object being compared. For a simple type like str I get:

            | s = "foo" | s = None
  ----------+-----------+----------
  s == None | 0.25 usec | 0.21 usec
  s is None | 0.17 usec | 0.17 usec

#!/bin/sh

# GNU diff is the reference for all of these results.

hgdiff() {
    echo hg diff $@
    hg diff --nodates "$@"
}

test_added_blank_lines() {
    printf '\nhello world\n\ngoodbye world\n\n' >foo

    echo '>>> two diffs showing three added lines <<<'
    hgdiff
    hgdiff -b

    echo '>>> no diffs <<<'
    hgdiff -B
    hgdiff -Bb
}

test_added_horizontal_space_first_on_a_line() {
    printf '\t hello world\ngoodbye world\n' >foo

    echo '>>> four diffs showing added space first on the first line <<<'
    hgdiff
    hgdiff -b
    hgdiff -B
    hgdiff -Bb
}

test_added_horizontal_space_last_on_a_line() {
    printf 'hello world\t \ngoodbye world\n' >foo

    echo '>>> two diffs showing space appended to the first line <<<'
    hgdiff
    hgdiff -B

    echo '>>> no diffs <<<'
    hgdiff -b
    hgdiff -Bb
}

test_added_horizontal_space_in_the_middle_of_a_word() {
    printf 'hello world\ngood bye world\n' >foo

    echo '>>> four diffs showing space inserted into "goodbye" <<<'
    hgdiff
    hgdiff -B
    hgdiff -b
    hgdiff -Bb
}

test_increased_horizontal_whitespace_amount() {
    printf 'hello world\ngoodbye\t\t  \tworld\n' >foo

    echo '>>> two diffs showing changed whitespace amount in the last line <<<'
    hgdiff
    hgdiff -B

    echo '>>> no diffs <<<'
    hgdiff -b
    hgdiff -Bb
}

test_added_blank_line_with_horizontal_whitespace() {
    printf 'hello world\n \t\ngoodbye world\n' >foo

    echo '>>> four diffs showing added blank line w/horizontal space <<<'
    hgdiff
    hgdiff -B
    hgdiff -b
    hgdiff -Bb
}

test_added_blank_line_with_other_whitespace() {
    printf 'hello  world\n \t\ngoodbye world \n' >foo

    echo '>>> three diffs showing added blank line w/other space <<<'
    hgdiff
    hgdiff -B
    hgdiff -b
    hgdiff -Bb
}

test_whitespace_changes() {
    printf 'helloworld\ngoodbye\tworld \n' >foo

    echo '>>> four diffs showing changed whitespace <<<'
    hgdiff
    hgdiff -B
    hgdiff -b
    hgdiff -Bb
    hgdiff -w
}

test_whitespace_changes_and_blank_lines() {
    printf 'helloworld\n\n\n\ngoodbye\tworld \n' >foo

    echo '>>> five diffs showing changed whitespace <<<'
    hgdiff
    hgdiff -B
    hgdiff -b
    hgdiff -Bb
    hgdiff -w
    hgdiff -wB
}

hg init
printf 'hello world\ngoodbye world\n' >foo
hg ci -Amfoo -ufoo

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