Enable `xmake show --format=json`

Fix: #7585

2 files changed, 27 insertions, 2 deletions

diff --git a/tests/plugins/show/test.lua b/tests/plugins/show/test.lua
index dea98c204..d7a59727a 100644
--- a/tests/plugins/show/test.lua
+++ b/tests/plugins/show/test.lua
@@ -1,5 +1,26 @@
 import("core.base.json")
 
+function test_list_targets_json_format(t)
+    local outdata = os.iorunv("xmake", {"show", "-l", "targets", "--format=json"})
+    local targets = json.decode(outdata)
+
+    t:require(table.contains(targets, "app"))
+    t:require(table.contains(targets, "core"))
+    t:require(table.contains(targets, "ui"))
+end
+
+function test_list_targets_plain_format(t)
+    local outdata = os.iorunv("xmake", {"show", "-l", "targets", "--format=plain"})
+    t:require(outdata:find("app", 1, true))
+    t:require(outdata:find("core", 1, true))
+    t:require(outdata:find("ui", 1, true))
+end
+
+function test_list_targets_unsupported_format(t)
+    local ok = try { function () os.execv("xmake", {"show", "-l", "targets", "--format=dot"}) end }
+    t:require(not ok)
+end
+
 function test_depgraph_json(t)
     local outdata = os.iorunv("xmake", {"show", "--info=depgraph", "--json"})
     local graph = json.decode(outdata)
diff --git a/xmake/plugins/show/showlist.lua b/xmake/plugins/show/showlist.lua
index 205ae21ed..6adda6bd0 100644
--- a/xmake/plugins/show/showlist.lua
+++ b/xmake/plugins/show/showlist.lua
@@ -49,9 +49,11 @@ function _show_json(values)
 end
 
 function main(values)
-    if option.get("json") then
+    local format = option.get("format")
+    -- List providers only support plain text and JSON output.
+    if option.get("json") or format == "json" then
         _show_json(values)
-    else
+    elseif format == nil or format == "plain" then
         if table.is_dictionary(values) then
             for k, v in pairs(values) do
                 cprint("${bright}%s:", k)
@@ -60,5 +62,7 @@ function main(values)
         else
             _show_text(values)
         end
+    else
+        raise("unsupported list output format: %s", format)
     end
 end