fix: support extra_lua_path in test framework

docs/en/latest/internal/testing-framework.md

@@ -111,6 +111,27 @@ GET /index.html
 no valid upstream node
 ```
 
+## Custom Lua Paths
+
+To test custom plugins in custom directories, you can specify custom Lua paths:
+
+**Using block definitions:**
+
+```
+--- extra_lua_path: /custom/path/?.lua
+--- extra_lua_cpath: /custom/path/?.so
+```
+
+**Using YAML config:**
+
+```
+--- extra_yaml_config
+apisix:
+  extra_lua_path: "/custom/path/?.lua"
+```
+
+Block definitions take precedence over YAML config when both are provided.
+
 ## Preparing the upstream
 
 To test the code, we need to provide a mock upstream.

t/APISIX.pm

@@ -307,9 +307,53 @@ deployment:
 _EOC_
     }
 
+    my $extra_lua_path = "";
+    my $extra_lua_cpath = "";
+
+    # Support for extra_lua_path / extra_lua_cpath:
+    # These allow tests to load custom plugins from non-standard directories.
+    #
+    # Method 1 - Block definition (preferred, takes precedence):
+    #   --- extra_lua_path
+    #   /path/to/custom/plugins/?.lua;
+    #
+    # Method 2 - Via extra_yaml_config:
+    #   --- extra_yaml_config
+    #   apisix:
+    #     extra_lua_path: "/path/to/custom/plugins/?.lua;"
+    #
+    # The extracted paths are prepended to lua_package_path / lua_package_cpath,
+    # consistent with the runtime behavior in apisix/cli/ops.lua.
+
+    # Method 1: Block definition (preferred)
+    if ($block->extra_lua_path) {
+        $extra_lua_path = $block->extra_lua_path;
+        $extra_lua_path .= ";" unless $extra_lua_path =~ /;$/;
+    }
+    if ($block->extra_lua_cpath) {
+        $extra_lua_cpath = $block->extra_lua_cpath;
+        $extra_lua_cpath .= ";" unless $extra_lua_cpath =~ /;$/;
+    }
+
+    # Method 2: Extract from extra_yaml_config if block definition not provided
+    if (!$extra_lua_path && $block->extra_yaml_config) {
+        my $extra_yaml = $block->extra_yaml_config;
+        if ($extra_yaml =~ m/^\s*extra_lua_path:\s*["\']?([^"\'\n]+)["\']?/m) {
+            $extra_lua_path = $1;
+            $extra_lua_path .= ";" unless $extra_lua_path =~ /;$/;
+        }
+    }
+    if (!$extra_lua_cpath && $block->extra_yaml_config) {
+        my $extra_yaml = $block->extra_yaml_config;
+        if ($extra_yaml =~ m/^\s*extra_lua_cpath:\s*["\']?([^"\'\n]+)["\']?/m) {
+            $extra_lua_cpath = $1;
+            $extra_lua_cpath .= ";" unless $extra_lua_cpath =~ /;$/;
+        }
+    }
+
     my $lua_deps_path = $block->lua_deps_path // <<_EOC_;
-    lua_package_path "$apisix_home/?.lua;$apisix_home/?/init.lua;$apisix_home/deps/share/lua/5.1/?/init.lua;$apisix_home/deps/share/lua/5.1/?.lua;$apisix_home/apisix/?.lua;$apisix_home/t/?.lua;$apisix_home/t/xrpc/?.lua;$apisix_home/t/xrpc/?/init.lua;;";
-    lua_package_cpath "$apisix_home/?.so;$apisix_home/deps/lib/lua/5.1/?.so;$apisix_home/deps/lib64/lua/5.1/?.so;;";
+    lua_package_path "$extra_lua_path$apisix_home/?.lua;$apisix_home/?/init.lua;$apisix_home/deps/share/lua/5.1/?/init.lua;$apisix_home/deps/share/lua/5.1/?.lua;$apisix_home/apisix/?.lua;$apisix_home/t/?.lua;$apisix_home/t/xrpc/?.lua;$apisix_home/t/xrpc/?/init.lua;;";
+    lua_package_cpath "$extra_lua_cpath$apisix_home/?.so;$apisix_home/deps/lib/lua/5.1/?.so;$apisix_home/deps/lib64/lua/5.1/?.so;;";
 _EOC_
 
     my $main_config = $block->main_config // <<_EOC_;