fix: fix custom folding markers to work with strings

Author: CGNonofr

src/hacks.ts

@@ -1,22 +1,50 @@
 
-import * as monaco from 'monaco-editor'
-
 /* Add custom blocks parsing (for tech.io):
 // { [autofold]
 //  custom block content
 // }
 */
 const CUSTOM_BLOCK_BEGIN_REGEX = '^\\s*(?:\\/\\/|#).*(?:\\{|#region)'
 const CUSTOM_BLOCK_END_REGEX = '^\\s*(?:\\/\\/|#).*(?:\\}|#endregion)'
-export function addCustomFoldingMarkers (configuration: monaco.extra.ILanguageConfiguration): monaco.extra.ILanguageConfiguration {
+
+interface IRegExp {
+  pattern: string
+  flags?: string
+}
+export interface ILanguageConfiguration {
+  folding?: {
+    offSide?: boolean
+    markers?: {
+      start?: string | IRegExp
+      end?: string | IRegExp
+    }
+  }
+}
+
+function regexOr (regex: string, add: string): string
+function regexOr (regex: undefined | string | IRegExp, add: string): string | IRegExp
+function regexOr (regex: undefined | string | IRegExp, add: string): string | IRegExp {
+  if (regex == null) {
+    return add
+  } else if (typeof regex === 'string') {
+    return `(?:${regex})|(?:${add})`
+  } else {
+    return {
+      flags: regex.flags,
+      pattern: regexOr(regex.pattern, add)
+    }
+  }
+}
+
+export function addCustomFoldingMarkers<T extends ILanguageConfiguration> (configuration: T): T {
   const markers = configuration.folding?.markers
   return {
     ...configuration,
     folding: {
       ...configuration.folding ?? {},
       markers: {
-        start: markers != null ? new RegExp(markers.start.source + '|' + CUSTOM_BLOCK_BEGIN_REGEX) : new RegExp(CUSTOM_BLOCK_BEGIN_REGEX),
-        end: markers != null ? new RegExp(markers.end.source + '|' + CUSTOM_BLOCK_END_REGEX) : new RegExp(CUSTOM_BLOCK_END_REGEX)
+        start: regexOr(markers?.start, CUSTOM_BLOCK_BEGIN_REGEX),
+        end: regexOr(markers?.end, CUSTOM_BLOCK_END_REGEX)
       }
     }
   }