fixed #602

Author: Code-Hex

src/directive.ts

@@ -182,10 +182,15 @@ function stringify(arg: any, quoteString?: boolean): string {
     if (isConvertableRegexp(arg))
       return arg;
 
+    const v = tryEval(arg)
+    if (v !== undefined)
+      arg = v
+
     if (quoteString)
       return JSON.stringify(arg);
   }
-  if (typeof arg === 'boolean' || typeof arg === 'number' || typeof arg === 'bigint')
+
+  if (typeof arg === 'boolean' || typeof arg === 'number' || typeof arg === 'bigint' || arg === 'undefined' || arg === null)
     return `${arg}`;
 
   return JSON.stringify(arg);
@@ -199,6 +204,16 @@ function apiArgsFromConstValueNode(value: ConstValueNode): any[] {
   return [val];
 }
 
+function tryEval(maybeValidJavaScript: string): any | undefined {
+  try {
+    // eslint-disable-next-line no-eval
+    return eval(maybeValidJavaScript)
+  }
+  catch {
+    return undefined
+  }
+}
+
 export const exportedForTesting = {
   applyArgToApiSchemaTemplate,
   buildApiFromDirectiveObjectArguments,

tests/directive.spec.ts

@@ -190,6 +190,38 @@ describe('format directive config', () => {
         },
         want: 'true',
       },
+      {
+        name: 'eval number',
+        args: {
+          template: '$1',
+          apiArgs: ['10 + 1'],
+        },
+        want: '11',
+      },
+      {
+        name: 'eval boolean',
+        args: {
+          template: '$1',
+          apiArgs: ['!true'],
+        },
+        want: 'false',
+      },
+      {
+        name: 'eval template with number',
+        args: {
+          template: '$1 + 1',
+          apiArgs: [10],
+        },
+        want: '11',
+      },
+      {
+        name: 'eval template with boolean',
+        args: {
+          template: '$1 && false',
+          apiArgs: [true],
+        },
+        want: 'false',
+      },
       {
         name: 'array',
         args: {
@@ -206,6 +238,22 @@ describe('format directive config', () => {
         },
         want: `{"hello":"world"}`,
       },
+      {
+        name: 'undefined',
+        args: {
+          template: '$1',
+          apiArgs: ['undefined'],
+        },
+        want: 'undefined',
+      },
+      {
+        name: 'null',
+        args: {
+          template: '$1',
+          apiArgs: ['null'],
+        },
+        want: 'null',
+      },
       {
         name: 'multiple',
         args: {