feat: add options args to fm

Author: tyankatsu0105

index.d.ts

@@ -5,8 +5,16 @@ export interface FrontMatterResult<T> {
   readonly frontmatter?: string
 }
 
+export interface FrontMatterOptions {
+  /**
+   * Whether to use [safeload](https://github.com/nodeca/js-yaml#safeload-string---options-)
+   * @default true
+   */
+  allowUnsafe?: boolean
+}
+
 interface FM {
-  <T>(file: string): FrontMatterResult<T>
+  <T>(file: string, options?: FrontMatterOptions): FrontMatterResult<T>
   test(file: string): boolean
 }
 

test/index.errors.ts

@@ -19,7 +19,7 @@ let nullBox: null;
   /* ===================== fm ===================== */
 
   {
-    // THROWS 1 arguments, but got 0.
+    // THROWS Expected 1-2 arguments, but got 0.
     fm()
   }
 
@@ -28,6 +28,11 @@ let nullBox: null;
     fm(null)
   }
 
+  {
+    // THROWS 'string' is not assignable to type 'boolean | undefined'.
+    fm(file, {allowUnsafe: 'yes'})
+  }
+
   {
 
     // THROWS 'FrontMatterResult<unknown>' is not assignable to type 'null'.
@@ -69,7 +74,6 @@ let nullBox: null;
   }
 
   {
-
     // THROWS Type 'boolean' is not assignable to type 'null'.
     nullBox = fm.test(file)
   }

test/index.types.ts

@@ -28,6 +28,14 @@ This is some text about some stuff that happened sometime ago`;
     console.log(bodyBegin);
     console.log(frontmatter);
   }
+
+  {
+    fm(file)
+  }
+
+  {
+    fm(file, {allowUnsafe: true})
+  }
 }
 
 {