58 lines
2.5 KiB
Plaintext
58 lines
2.5 KiB
Plaintext
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diff-highlight
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==============
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Line oriented diffs are great for reviewing code, because for most
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hunks, you want to see the old and the new segments of code next to each
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other. Sometimes, though, when an old line and a new line are very
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similar, it's hard to immediately see the difference.
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You can use "--color-words" to highlight only the changed portions of
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lines. However, this can often be hard to read for code, as it loses
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the line structure, and you end up with oddly formatted bits.
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Instead, this script post-processes the line-oriented diff, finds pairs
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of lines, and highlights the differing segments. It's currently very
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simple and stupid about doing these tasks. In particular:
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1. It will only highlight a pair of lines if they are the only two
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lines in a hunk. It could instead try to match up "before" and
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"after" lines for a given hunk into pairs of similar lines.
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However, this may end up visually distracting, as the paired
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lines would have other highlighted lines in between them. And in
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practice, the lines which most need attention called to their
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small, hard-to-see changes are touching only a single line.
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2. It will find the common prefix and suffix of two lines, and
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consider everything in the middle to be "different". It could
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instead do a real diff of the characters between the two lines and
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find common subsequences. However, the point of the highlight is to
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call attention to a certain area. Even if some small subset of the
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highlighted area actually didn't change, that's OK. In practice it
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ends up being more readable to just have a single blob on the line
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showing the interesting bit.
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The goal of the script is therefore not to be exact about highlighting
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changes, but to call attention to areas of interest without being
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visually distracting. Non-diff lines and existing diff coloration is
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preserved; the intent is that the output should look exactly the same as
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the input, except for the occasional highlight.
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Use
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---
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You can try out the diff-highlight program with:
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---------------------------------------------
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git log -p --color | /path/to/diff-highlight
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---------------------------------------------
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If you want to use it all the time, drop it in your $PATH and put the
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following in your git configuration:
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---------------------------------------------
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[pager]
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log = diff-highlight | less
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show = diff-highlight | less
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diff = diff-highlight | less
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---------------------------------------------
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