diff-highlight: add multi-byte tests
Now that we have a test suite for diff highlight, we can show off the improvements from 8d00662 (diff-highlight: do not split multibyte characters, 2015-04-03). While we're at it, we can also add another case that _doesn't_ work: combining code points are treated as their own unit, which means that we may stick colors between them and the character they are modifying (with the result that the color is not shown in an xterm, though it's possible that other terminals err the other way, and show the color but not the accent). There's no fix here, but let's document it as a failure. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King committed
Aug 31, 2016 at 01:03 UTC
1b5290b125fca91f620aadbc1a5e3c559d4a5313
1 file changed
+35
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contrib/diff-highlight/t/t9400-diff-highlight.sh
+35
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@@ -207,7 +207,41 @@ test_expect_failure 'diff-highlight highlights mismatched hunk size' '
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EOF
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'
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-# TODO add multi-byte test
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+# These two code points share the same leading byte in UTF-8 representation;
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+# a naive byte-wise diff would highlight only the second byte.
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+#
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+# - U+00f3 ("o" with acute)
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+o_accent=$(printf '\303\263')
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+# - U+00f8 ("o" with stroke)
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+o_stroke=$(printf '\303\270')
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+
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+test_expect_success 'diff-highlight treats multibyte utf-8 as a unit' '
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+ echo "unic${o_accent}de" >a &&
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+ echo "unic${o_stroke}de" >b &&
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+ dh_test a b <<-EOF
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+ @@ -1 +1 @@
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+ -unic${CW}${o_accent}${CR}de
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+ +unic${CW}${o_stroke}${CR}de
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+ EOF
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+'
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+
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+# Unlike the UTF-8 above, these are combining code points which are meant
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+# to modify the character preceding them:
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+#
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+# - U+0301 (combining acute accent)
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+combine_accent=$(printf '\314\201')
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+# - U+0302 (combining circumflex)
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+combine_circum=$(printf '\314\202')
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+
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+test_expect_failure 'diff-highlight treats combining code points as a unit' '
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+ echo "unico${combine_accent}de" >a &&
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+ echo "unico${combine_circum}de" >b &&
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+ dh_test a b <<-EOF
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+ @@ -1 +1 @@
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+ -unic${CW}o${combine_accent}${CR}de
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+ +unic${CW}o${combine_circum}${CR}de
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+ EOF
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+'
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test_expect_success 'diff-highlight works with the --graph option' '
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dh_test_setup_history &&