[PATCH] Introduce unit tests for git-rev-list --bisect

This patch introduces some unit tests for the git-rev-list --bisect functionality.

Signed-off-by: Jon Seymour <jon.seymour@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/t/t6002-rev-list-bisect.sh b/t/t6002-rev-list-bisect.sh
new file mode 100755 (executable)
index 0000000..dde5d86
--- /dev/null
+++ b/t/t6002-rev-list-bisect.sh
@@ -0,0 +1,247 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Jon Seymour
+#
+test_description='Tests git-rev-list --bisect functionality'
+
+. ./test-lib.sh
+. ../t6000-lib.sh
+
+bc_expr()
+{
+bc <<EOF
+scale=1
+define abs(x) { if (x>=0) { return x; } else { return -x; } }
+define floor(x) { save=scale; scale=0; result=x/1; scale=save; return result; }
+$*
+EOF
+}
+
+# usage: test_bisection max-diff bisect-option head ^prune...
+#
+# e.g. test_bisection 1 --bisect l1 ^l0
+#
+test_bisection_diff()
+{
+       _max_diff=$1
+       _bisect_option=$2
+       shift 2
+       _bisection=$(git-rev-list $_bisect_option "$@")
+       _list_size=$(git-rev-list "$@" | wc -l)
+        _head=$1
+       shift 1
+       _bisection_size=$(git-rev-list $_bisection "$@" | wc -l)
+       [ -n "$_list_size" -a -n "$_bisection_size" ] || error "test_bisection_diff failed"
+       test_expect_success "bisection diff $_bisect_option $_head $* <= $_max_diff" "[ $(bc_expr "floor(abs($_list_size/2)-$_bisection_size)") -le $_max_diff ]"
+}
+
+date >path0
+git-update-cache --add path0
+save_tag tree git-write-tree
+on_committer_date "1971-08-16 00:00:00" hide_error save_tag root unique_commit root tree
+on_committer_date "1971-08-16 00:00:01" save_tag l0 unique_commit l0 tree -p root
+on_committer_date "1971-08-16 00:00:02" save_tag l1 unique_commit l1 tree -p l0
+on_committer_date "1971-08-16 00:00:03" save_tag l2 unique_commit l2 tree -p l1
+on_committer_date "1971-08-16 00:00:04" save_tag a0 unique_commit a0 tree -p l2
+on_committer_date "1971-08-16 00:00:05" save_tag a1 unique_commit a1 tree -p a0
+on_committer_date "1971-08-16 00:00:06" save_tag b1 unique_commit b1 tree -p a0
+on_committer_date "1971-08-16 00:00:07" save_tag c1 unique_commit c1 tree -p b1
+on_committer_date "1971-08-16 00:00:08" save_tag b2 unique_commit b2 tree -p b1
+on_committer_date "1971-08-16 00:00:09" save_tag b3 unique_commit b2 tree -p b2
+on_committer_date "1971-08-16 00:00:10" save_tag c2 unique_commit c2 tree -p c1 -p b2
+on_committer_date "1971-08-16 00:00:11" save_tag c3 unique_commit c3 tree -p c2
+on_committer_date "1971-08-16 00:00:12" save_tag a2 unique_commit a2 tree -p a1
+on_committer_date "1971-08-16 00:00:13" save_tag a3 unique_commit a3 tree -p a2
+on_committer_date "1971-08-16 00:00:14" save_tag b4 unique_commit b4 tree -p b3 -p a3
+on_committer_date "1971-08-16 00:00:15" save_tag a4 unique_commit a4 tree -p a3 -p b4 -p c3
+on_committer_date "1971-08-16 00:00:16" save_tag l3 unique_commit l3 tree -p a4
+on_committer_date "1971-08-16 00:00:17" save_tag l4 unique_commit l4 tree -p l3
+on_committer_date "1971-08-16 00:00:18" save_tag l5 unique_commit l5 tree -p l4
+tag l5 > .git/HEAD
+
+
+#     E
+#    / \
+#   e1  |
+#   |   |
+#   e2  |
+#   |   |
+#   e3  |
+#   |   |
+#   e4  |
+#   |   |
+#   |   f1
+#   |   |
+#   |   f2
+#   |   |
+#   |   f3
+#   |   |
+#   |   f4
+#   |   |
+#   e5  |
+#   |   |
+#   e6  |
+#   |   |
+#   e7  |
+#   |   |
+#   e8  |
+#    \ /
+#     F
+
+
+on_committer_date "1971-08-16 00:00:00" hide_error save_tag F unique_commit F tree
+on_committer_date "1971-08-16 00:00:01" save_tag e8 unique_commit e8 tree -p F
+on_committer_date "1971-08-16 00:00:02" save_tag e7 unique_commit e7 tree -p e8
+on_committer_date "1971-08-16 00:00:03" save_tag e6 unique_commit e6 tree -p e7
+on_committer_date "1971-08-16 00:00:04" save_tag e5 unique_commit e5 tree -p e6
+on_committer_date "1971-08-16 00:00:05" save_tag f4 unique_commit f4 tree -p F
+on_committer_date "1971-08-16 00:00:06" save_tag f3 unique_commit f3 tree -p f4
+on_committer_date "1971-08-16 00:00:07" save_tag f2 unique_commit f2 tree -p f3
+on_committer_date "1971-08-16 00:00:08" save_tag f1 unique_commit f1 tree -p f2
+on_committer_date "1971-08-16 00:00:09" save_tag e4 unique_commit e4 tree -p e5
+on_committer_date "1971-08-16 00:00:10" save_tag e3 unique_commit e3 tree -p e4
+on_committer_date "1971-08-16 00:00:11" save_tag e2 unique_commit e2 tree -p e3
+on_committer_date "1971-08-16 00:00:12" save_tag e1 unique_commit e1 tree -p e2
+on_committer_date "1971-08-16 00:00:13" save_tag E unique_commit E tree -p e1 -p f1
+
+on_committer_date "1971-08-16 00:00:00" hide_error save_tag U unique_commit U tree
+on_committer_date "1971-08-16 00:00:01" save_tag u0 unique_commit u0 tree -p U
+on_committer_date "1971-08-16 00:00:01" save_tag u1 unique_commit u1 tree -p u0
+on_committer_date "1971-08-16 00:00:02" save_tag u2 unique_commit u2 tree -p u0
+on_committer_date "1971-08-16 00:00:03" save_tag u3 unique_commit u3 tree -p u0
+on_committer_date "1971-08-16 00:00:04" save_tag u4 unique_commit u4 tree -p u0
+on_committer_date "1971-08-16 00:00:05" save_tag u5 unique_commit u5 tree -p u0
+on_committer_date "1971-08-16 00:00:06" save_tag V unique_commit V tree -p u1 -p u2 -p u3 -p u4 -p u5
+
+
+#
+# cd to t/trash and use 
+#
+#    git-rev-list ... 2>&1 | sed "$(cat sed.script)" 
+#
+# if you ever want to manually debug the operation of git-rev-list
+#
+echo $sed_script > sed.script
+
+test_sequence()
+{
+       _bisect_option=$1       
+       
+       test_bisection_diff 0 $_bisect_option l0 ^root
+       test_bisection_diff 0 $_bisect_option l1 ^root
+       test_bisection_diff 0 $_bisect_option l2 ^root
+       test_bisection_diff 0 $_bisect_option a0 ^root
+       test_bisection_diff 0 $_bisect_option a1 ^root
+       test_bisection_diff 0 $_bisect_option a2 ^root
+       test_bisection_diff 0 $_bisect_option a3 ^root
+       test_bisection_diff 0 $_bisect_option b1 ^root
+       test_bisection_diff 0 $_bisect_option b2 ^root
+       test_bisection_diff 0 $_bisect_option b3 ^root
+       test_bisection_diff 0 $_bisect_option c1 ^root
+       test_bisection_diff 0 $_bisect_option c2 ^root
+       test_bisection_diff 0 $_bisect_option c3 ^root
+       test_bisection_diff 0 $_bisect_option E ^F
+       test_bisection_diff 0 $_bisect_option e1 ^F
+       test_bisection_diff 0 $_bisect_option e2 ^F
+       test_bisection_diff 0 $_bisect_option e3 ^F
+       test_bisection_diff 0 $_bisect_option e4 ^F
+       test_bisection_diff 0 $_bisect_option e5 ^F
+       test_bisection_diff 0 $_bisect_option e6 ^F
+       test_bisection_diff 0 $_bisect_option e7 ^F
+       test_bisection_diff 0 $_bisect_option f1 ^F
+       test_bisection_diff 0 $_bisect_option f2 ^F
+       test_bisection_diff 0 $_bisect_option f3 ^F
+       test_bisection_diff 0 $_bisect_option f4 ^F
+       test_bisection_diff 0 $_bisect_option E ^F
+
+       test_bisection_diff 1 $_bisect_option V ^U
+       test_bisection_diff 0 $_bisect_option V ^U ^u1 ^u2 ^u3
+       test_bisection_diff 0 $_bisect_option u1 ^U
+       test_bisection_diff 0 $_bisect_option u2 ^U
+       test_bisection_diff 0 $_bisect_option u3 ^U
+       test_bisection_diff 0 $_bisect_option u4 ^U
+       test_bisection_diff 0 $_bisect_option u5 ^U
+       
+#
+# the following illustrate's Linus' binary bug blatt idea. 
+#
+# assume the bug is actually at l3, but you don't know that - all you know is that l3 is broken
+# and it wasn't broken before
+#
+# keep bisecting the list, advancing the "bad" head and accumulating "good" heads until
+# the bisection point is the head - this is the bad point.
+#
+
+test_output_expect_success "--bisect l5 ^root" 'git-rev-list $_bisect_option l5 ^root' <<EOF
+c3
+EOF
+
+test_output_expect_success "$_bisect_option l5 ^root ^c3" 'git-rev-list $_bisect_option l5 ^root ^c3' <<EOF
+b4
+EOF
+
+test_output_expect_success "$_bisect_option l5 ^root ^c3 ^b4" 'git-rev-list $_bisect_option l5 ^c3 ^b4' <<EOF
+l3
+EOF
+
+test_output_expect_success "$_bisect_option l3 ^root ^c3 ^b4" 'git-rev-list $_bisect_option l3 ^root ^c3 ^b4' <<EOF
+a4
+EOF
+
+test_output_expect_success "$_bisect_option l5 ^b3 ^a3 ^b4 ^a4" 'git-rev-list $_bisect_option l3 ^b3 ^a3 ^a4' <<EOF
+l3
+EOF
+
+#
+# if l3 is bad, then l4 is bad too - so advance the bad pointer by making b4 the known bad head
+#
+
+test_output_expect_success "$_bisect_option l4 ^a2 ^a3 ^b ^a4" 'git-rev-list $_bisect_option l4 ^a2 ^a3 ^a4' <<EOF
+l3
+EOF
+
+test_output_expect_success "$_bisect_option l3 ^a2 ^a3 ^b ^a4" 'git-rev-list $_bisect_option l3 ^a2 ^a3 ^a4' <<EOF
+l3
+EOF
+
+# found!
+
+#
+# as another example, let's consider a4 to be the bad head, in which case
+#
+
+test_output_expect_success "$_bisect_option a4 ^a2 ^a3 ^b4" 'git-rev-list $_bisect_option a4 ^a2 ^a3 ^b4' <<EOF
+c2
+EOF
+
+test_output_expect_success "$_bisect_option a4 ^a2 ^a3 ^b4 ^c2" 'git-rev-list $_bisect_option a4 ^a2 ^a3 ^b4 ^c2' <<EOF
+c3
+EOF
+
+test_output_expect_success "$_bisect_option a4 ^a2 ^a3 ^b4 ^c2 ^c3" 'git-rev-list $_bisect_option a4 ^a2 ^a3 ^b4 ^c2 ^c3' <<EOF
+a4
+EOF
+
+# found!
+
+#
+# or consider c3 to be the bad head
+#
+
+test_output_expect_success "$_bisect_option a4 ^a2 ^a3 ^b4" 'git-rev-list $_bisect_option a4 ^a2 ^a3 ^b4' <<EOF
+c2
+EOF
+
+test_output_expect_success "$_bisect_option c3 ^a2 ^a3 ^b4 ^c2" 'git-rev-list $_bisect_option c3 ^a2 ^a3 ^b4 ^c2' <<EOF
+c3
+EOF
+
+# found!
+
+}
+
+test_sequence "--bisect"
+
+#
+#
+test_done