t4068: add --merge-base tests
In the future, we will be adding more --merge-base tests to this test
script. To prepare for that, rename the script accordingly and update
its description. Also, add two basic --merge-base tests that don't
require any functionality to be implemented yet.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t4068-diff-symmetric-merge-base.sh b/t/t4068-diff-symmetric-merge-base.sh
new file mode 100755
index 0000000..bd4cf25
--- /dev/null
+++ b/t/t4068-diff-symmetric-merge-base.sh
@@ -0,0 +1,100 @@
+#!/bin/sh
+
+test_description='behavior of diff with symmetric-diff setups and --merge-base'
+
+. ./test-lib.sh
+
+# build these situations:
+# - normal merge with one merge base (br1...b2r);
+# - criss-cross merge ie 2 merge bases (br1...master);
+# - disjoint subgraph (orphan branch, br3...master).
+#
+# B---E <-- master
+# / \ /
+# A X
+# \ / \
+# C---D--G <-- br1
+# \ /
+# ---F <-- br2
+#
+# H <-- br3
+#
+# We put files into a few commits so that we can verify the
+# output as well.
+
+test_expect_success setup '
+ git commit --allow-empty -m A &&
+ echo b >b &&
+ git add b &&
+ git commit -m B &&
+ git checkout -b br1 HEAD^ &&
+ echo c >c &&
+ git add c &&
+ git commit -m C &&
+ git tag commit-C &&
+ git merge -m D master &&
+ git tag commit-D &&
+ git checkout master &&
+ git merge -m E commit-C &&
+ git checkout -b br2 commit-C &&
+ echo f >f &&
+ git add f &&
+ git commit -m F &&
+ git checkout br1 &&
+ git merge -m G br2 &&
+ git checkout --orphan br3 &&
+ git commit -m H
+'
+
+test_expect_success 'diff with one merge base' '
+ git diff commit-D...br1 >tmp &&
+ tail -n 1 tmp >actual &&
+ echo +f >expect &&
+ test_cmp expect actual
+'
+
+# The output (in tmp) can have +b or +c depending
+# on which merge base (commit B or C) is picked.
+# It should have one of those two, which comes out
+# to seven lines.
+test_expect_success 'diff with two merge bases' '
+ git diff br1...master >tmp 2>err &&
+ test_line_count = 7 tmp &&
+ test_line_count = 1 err
+'
+
+test_expect_success 'diff with no merge bases' '
+ test_must_fail git diff br2...br3 2>err &&
+ test_i18ngrep "fatal: br2...br3: no merge base" err
+'
+
+test_expect_success 'diff with too many symmetric differences' '
+ test_must_fail git diff br1...master br2...br3 2>err &&
+ test_i18ngrep "usage" err
+'
+
+test_expect_success 'diff with symmetric difference and extraneous arg' '
+ test_must_fail git diff master br1...master 2>err &&
+ test_i18ngrep "usage" err
+'
+
+test_expect_success 'diff with two ranges' '
+ test_must_fail git diff master br1..master br2..br3 2>err &&
+ test_i18ngrep "usage" err
+'
+
+test_expect_success 'diff with ranges and extra arg' '
+ test_must_fail git diff master br1..master commit-D 2>err &&
+ test_i18ngrep "usage" err
+'
+
+test_expect_success 'diff --merge-base with no commits' '
+ test_must_fail git diff --merge-base
+'
+
+test_expect_success 'diff --merge-base with three commits' '
+ test_must_fail git diff --merge-base br1 br2 master 2>err &&
+ test_i18ngrep "usage" err
+'
+
+test_done
