builtin/config.c: support `--type=<type>` as preferred alias for `--<type>`

`git config` has long allowed the ability for callers to provide a 'type
specifier', which instructs `git config` to (1) ensure that incoming
values can be interpreted as that type, and (2) that outgoing values are
canonicalized under that type.

In another series, we propose to extend this functionality with
`--type=color` and `--default` to replace `--get-color`.

However, we traditionally use `--color` to mean "colorize this output",
instead of "this value should be treated as a color".

Currently, `git config` does not support this kind of colorization, but
we should be careful to avoid squatting on this option too soon, so that
`git config` can support `--color` (in the traditional sense) in the
future, if that is desired.

In this patch, we support `--type=<int|bool|bool-or-int|...>` in
addition to `--int`, `--bool`, and etc. This allows the aforementioned
upcoming patch to support querying a color value with a default via
`--type=color --default=...`, without squandering `--color`.

We retain the historic behavior of complaining when multiple,
legacy-style `--<type>` flags are given, as well as extend this to
conflicting new-style `--type=<type>` flags. `--int --type=int` (and its
commutative pair) does not complain, but `--bool --type=int` (and its
commutative pair) does.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 55 insertions, 3 deletions

diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index 24de37d..e06af3d 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -1613,13 +1613,65 @@ test_expect_success '--local requires a repo' '
 
 cat >.git/config <<-\EOF &&
 [core]
+foo = true
 number = 10
+big = 1M
 EOF
 
-test_expect_success 'later legacy specifiers are given precedence' '
-	git config --bool --int core.number >actual &&
-	echo 10 >expect &&
+test_expect_success 'identical modern --type specifiers are allowed' '
+	git config --type=int --type=int core.big >actual &&
+	echo 1048576 >expect &&
 	test_cmp expect actual
 '
 
+test_expect_success 'identical legacy --type specifiers are allowed' '
+	git config --int --int core.big >actual &&
+	echo 1048576 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'identical mixed --type specifiers are allowed' '
+	git config --int --type=int core.big >actual &&
+	echo 1048576 >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'non-identical modern --type specifiers are not allowed' '
+	test_must_fail git config --type=int --type=bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success 'non-identical legacy --type specifiers are not allowed' '
+	test_must_fail git config --int --bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success 'non-identical mixed --type specifiers are not allowed' '
+	test_must_fail git config --type=int --bool core.big 2>error &&
+	test_i18ngrep "only one type at a time" error
+'
+
+test_expect_success '--type allows valid type specifiers' '
+	echo "true" >expect &&
+	git config --type=bool core.foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--no-type unsets type specifiers' '
+	echo "10" >expect &&
+	git config --type=bool --no-type core.number >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'unset type specifiers may be reset to conflicting ones' '
+	echo 1048576 >expect &&
+	git config --type=bool --no-type --type=int core.big >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--type rejects unknown specifiers' '
+	test_must_fail git config --type=nonsense core.foo 2>error &&
+	test_i18ngrep "unrecognized --type argument" error
+'
+
 test_done