Allow placeholder to be changed

src/config.lsc

@@ -65,6 +65,10 @@ export getMetadata() ->
         description: "Specify arguments for a function using placeholders in the body."
         valueType: "boolean"
       }
+      placeholder: {
+        description: "Specify an identifier to be transformed into PlaceholderExpression."
+        valueType: "string"
+      }
     }
   }
 
@@ -88,6 +92,8 @@ export getParserOpts(pluginOpts, initialParserOpts) ->
   if pluginOpts?.enhancedComprehension: plugins.push("enhancedComprehension")
   if pluginOpts?.preferObjectLiteral: plugins.push("objectBlockAmbiguity_preferObject")
   if pluginOpts?.placeholderArgs: plugins.push("syntacticPlaceholder")
+  if pluginOpts?.placeholder:
+    parserOpts.placeholder = pluginOpts.placeholder
 
   // TODO: watch upstream on pattern matching; default to their syntax when complete
   // patternMatchingVersion = pluginOpts?.patternMatching or "v4"

test/fixtures/placeholder-args/change-placeholder-directive/actual.js

@@ -0,0 +1,3 @@
+'use @oigroup/lightscript with placeholder: "P"'
+
+-> P

test/fixtures/placeholder-args/change-placeholder-directive/expected.js

@@ -0,0 +1,5 @@
+'use @oigroup/lightscript with placeholder: "P"';
+
+(function (_arg) {
+  return _arg;
+});

test/fixtures/placeholder-args/change-placeholder-opts/actual.js

@@ -0,0 +1 @@
+-> P

test/fixtures/placeholder-args/change-placeholder-opts/expected.js

@@ -0,0 +1,3 @@
+(function (_arg) {
+  return _arg;
+});

test/fixtures/placeholder-args/change-placeholder-opts/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": [["lightscript", { "placeholderArgs": true, "placeholder": "P" }]]
+}