feat(shared): support Map and Set in toDisplayString

close #1067, close #1100

packages/shared/src/toDisplayString.ts

@@ -0,0 +1,28 @@
+import { isArray, isObject, isPlainObject } from './index'
+
+// For converting {{ interpolation }} values to displayed strings.
+export const toDisplayString = (val: unknown): string => {
+  return val == null
+    ? ''
+    : isObject(val)
+      ? JSON.stringify(val, replacer, 2)
+      : String(val)
+}
+
+const replacer = (_key: string, val: any) => {
+  if (val instanceof Map) {
+    return {
+      [`Map(${val.size})`]: [...val.entries()].reduce((entries, [key, val]) => {
+        ;(entries as any)[`${key} =>`] = val
+        return entries
+      }, {})
+    }
+  } else if (val instanceof Set) {
+    return {
+      [`Set(${val.size})`]: [...val.values()]
+    }
+  } else if (isObject(val) && !isArray(val) && !isPlainObject(val)) {
+    return String(val)
+  }
+  return val
+}