#! /bin/sh

# Test a bunch of scenarios where branch `b` has a pair of commits,

# the first of which conflicts with branch `a`, and the second of

# which reverts that change. This tests the code for backtracking when

# outlining. We try placing the conflict-revert pair at the beginning,

# the middle, and the end of branch `b`, and we try merging both `b`

# into `a` and `a` into `b`.

set -ex

BASE="$(dirname "$(cd $(dirname "$0") && pwd)")"

. "$BASE/t/test-lib.sh"

GIT_IMERGE="git-imerge"

test_merge() {

# The name of this test:

local name=$1

# The name of the branch being merged into:

local dst=$2

# The name of the branch being merged from:

local src=$3

# The indexes of the first and second conflicting micromerges

# (e.g., "2-1"):

local conflict1=$4

local conflict2=$5

# Test merging branch `$dst` into `$src`:

git checkout $dst

"$GIT_IMERGE" merge --branch=$name $src 2>&1 | tee imerge-$name-1.out

"$GIT_IMERGE" diagram --commits --frontier

if ! grep -q "There was a conflict merging commit $conflict1" imerge-$name-1.out

then

echo "conflict at $conflict1 not detected"

exit 1

fi

# Fix the first conflict:

echo 1 >a.txt

git add a.txt

"$GIT_IMERGE" continue --no-edit 2>&1 | tee imerge-$name-2.out

"$GIT_IMERGE" diagram --commits --frontier

if ! grep -q "There was a conflict merging commit $conflict2" imerge-$name-2.out

then

echo "conflict at $conflict2 not detected"

exit 1

fi

# Fix the second conflict:

echo 1 >a.txt

git add a.txt

"$GIT_IMERGE" continue --no-edit 2>&1 | tee imerge-$name-3.out

if ! grep -q 'Merge is complete' imerge-$name-3.out

then

echo "merge failed"

exit 1

fi

"$GIT_IMERGE" diagram --commits --frontier

GIT_EDITOR=cat "$GIT_IMERGE" finish

}

flip_flop_test () {

local n="$1"

TMP="$BASE/t/tmp/flip-flop-$n"

DESCRIPTION="git-imerge test repository with a commit and its revert at n=$n"

init_test_repo "$TMP" "$DESCRIPTION"

cd "$TMP"

modify a.txt 0

commit -m 'm⇒0'

git checkout -b a --

for i in 1 2 3

do

modify a.txt $i

commit -m "a⇒$i on branch a"

done

git checkout -b b master --

for i in 1 2 3 4

do

modify b.txt $i

msg="b⇒$i"

if test $i = $n

then

modify a.txt X

msg="$msg and a⇒X"

fi

if test $i = $(( n + 1 ))

then

modify a.txt 0

msg="$msg and a⇒0"

fi

commit -m "$msg on branch b"

done

# Test merging `b` into `a`:

test_merge "b-into-a-$n" a b "1-$n" "1-$(( n + 1 ))"

# Test merging `a` into `b`:

test_merge "a-into-b-$n" b a "$n-1" "$(( n + 1 ))-1"

}

for n in 1 2 3

do

flip_flop_test $n

done