- add logic which cleans up custom placeholders with the [] syntax which were not matched

src/transform.ts

@@ -255,6 +255,7 @@ export function buildChangelog(diffInfo: DiffInfo, prs: PullRequestInfo[], optio
   let transformedChangelog = config.template || DefaultConfiguration.template
   transformedChangelog = replacePlaceholders(transformedChangelog, placeholderMap, placeholders, placeholderPrMap)
   transformedChangelog = replacePrPlaceholders(transformedChangelog, placeholderPrMap)
+  transformedChangelog = cleanupPrPlaceHolders(transformedChangelog, placeholders)
   core.info(`ℹ️ Filled template`)
   return transformedChangelog
 }
@@ -361,6 +362,19 @@ function replacePrPlaceholders(
   return transformed
 }
 
+function cleanupPrPlaceHolders(
+  template: string,
+  placeholders: Map<string, Placeholder[]> /* placeholders to apply */
+): string {
+  let transformed = template
+  for (const [, phs] of placeholders) {
+    for (const ph of phs) {
+      transformed = transformed.replaceAll(new RegExp(`\\$\\{\\{${ph.name}\\[.+?\\]\\}\\}`, 'gu'), '')
+    }
+  }
+  return transformed
+}
+
 function transform(filled: string, transformers: RegexTransformer[]): string {
   if (transformers.length === 0) {
     return filled