Teach diff a new algorithm, one that attempts to prevent user-specified lines from appearing as a deletion or addition in the end result. The end user can use this by specifying "--anchored=<text>" one or more times when using Git commands like "diff" and "show". Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
			
				
	
	
		
			95 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			95 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Bash
		
	
	
		
			Executable File
		
	
	
	
	
#!/bin/sh
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test_description='anchored diff algorithm'
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. ./test-lib.sh
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test_expect_success '--anchored' '
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	printf "a\nb\nc\n" >pre &&
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	printf "c\na\nb\n" >post &&
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	# normally, c is moved to produce the smallest diff
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	test_expect_code 1 git diff --no-index pre post >diff &&
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	grep "^+c" diff &&
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	# with anchor, a is moved
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	test_expect_code 1 git diff --no-index --anchored=c pre post >diff &&
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	grep "^+a" diff
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'
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test_expect_success '--anchored multiple' '
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	printf "a\nb\nc\nd\ne\nf\n" >pre &&
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	printf "c\na\nb\nf\nd\ne\n" >post &&
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	# with 1 anchor, c is not moved, but f is moved
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	test_expect_code 1 git diff --no-index --anchored=c pre post >diff &&
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	grep "^+a" diff && # a is moved instead of c
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	grep "^+f" diff &&
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	# with 2 anchors, c and f are not moved
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	test_expect_code 1 git diff --no-index --anchored=c --anchored=f pre post >diff &&
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	grep "^+a" diff &&
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	grep "^+d" diff # d is moved instead of f
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'
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test_expect_success '--anchored with nonexistent line has no effect' '
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	printf "a\nb\nc\n" >pre &&
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	printf "c\na\nb\n" >post &&
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	test_expect_code 1 git diff --no-index --anchored=x pre post >diff &&
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	grep "^+c" diff
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'
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test_expect_success '--anchored with non-unique line has no effect' '
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	printf "a\nb\nc\nd\ne\nc\n" >pre &&
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	printf "c\na\nb\nc\nd\ne\n" >post &&
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	test_expect_code 1 git diff --no-index --anchored=c pre post >diff &&
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	grep "^+c" diff
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'
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test_expect_success 'diff still produced with impossible multiple --anchored' '
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	printf "a\nb\nc\n" >pre &&
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	printf "c\na\nb\n" >post &&
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	test_expect_code 1 git diff --no-index --anchored=a --anchored=c pre post >diff &&
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	mv post expected_post &&
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	# Ensure that the diff is correct by applying it and then
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	# comparing the result with the original
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	git apply diff &&
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	diff expected_post post
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'
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test_expect_success 'later algorithm arguments override earlier ones' '
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	printf "a\nb\nc\n" >pre &&
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	printf "c\na\nb\n" >post &&
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	test_expect_code 1 git diff --no-index --patience --anchored=c pre post >diff &&
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	grep "^+a" diff &&
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	test_expect_code 1 git diff --no-index --anchored=c --patience pre post >diff &&
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	grep "^+c" diff &&
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	test_expect_code 1 git diff --no-index --histogram --anchored=c pre post >diff &&
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	grep "^+a" diff &&
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	test_expect_code 1 git diff --no-index --anchored=c --histogram pre post >diff &&
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	grep "^+c" diff
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'
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test_expect_success '--anchored works with other commands like "git show"' '
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	printf "a\nb\nc\n" >file &&
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	git add file &&
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	git commit -m foo &&
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	printf "c\na\nb\n" >file &&
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	git add file &&
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	git commit -m foo &&
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	# with anchor, a is moved
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	git show --patience --anchored=c >diff &&
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	grep "^+a" diff
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'
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test_done
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