fix: throw an error when passing an object to compile instead of a function notation ["object", {...}]

josdejong · josdejong · commit 615393a35e31 · 2024-11-29T13:06:24.000+01:00
diff --git a/src/compile.test.ts b/src/compile.test.ts
@@ -54,6 +54,21 @@ describe('error handling', () => {
     expect(actualErr?.message).toBe("Unknown function 'foo'")
   })
 
+  test('should throw a helpful error when passing an object {...} instead of function ["object", {...}]', () => {
+    let actualErr = undefined
+    const user = { name: 'Joe' }
+    const query = { name: ['get', 'name'] }
+    try {
+      go(user, query)
+    } catch (err) {
+      actualErr = err
+    }
+
+    expect(actualErr?.message).toBe(
+      'Function notation ["object", {...}] expected but got {"name":["get","name"]}'
+    )
+  })
+
   test('should throw a helpful error when a pipe contains a runtime error', () => {
     const scoreData = {
       participants: [
diff --git a/src/compile.ts b/src/compile.ts
@@ -1,5 +1,5 @@
 import { functions } from './functions'
-import { isArray } from './is'
+import { isArray, isObject } from './is'
 import type {
   Fun,
   FunctionBuildersMap,
@@ -16,7 +16,11 @@ export function compile(query: JSONQuery, options?: JSONQueryCompileOptions): Fu
   try {
     const exec = isArray(query)
       ? compileFunction(query as JSONQueryFunction, functionsStack[0]) // function
-      : () => query // primitive value (string, number, boolean, null)
+      : isObject(query)
+        ? throwTypeError(
+            `Function notation ["object", {...}] expected but got ${JSON.stringify(query)}`
+          )
+        : () => query // primitive value (string, number, boolean, null)
 
     // create a wrapper function which can attach a stack to the error
     return (data) => {
@@ -39,8 +43,12 @@ function compileFunction(query: JSONQueryFunction, functions: FunctionBuildersMa
 
   const fnBuilder = functions[fnName]
   if (!fnBuilder) {
-    throw new Error(`Unknown function '${fnName}'`)
+    throwTypeError(`Unknown function '${fnName}'`)
   }
 
   return fnBuilder(...args)
 }
+
+function throwTypeError(message: string): () => void {
+  throw new Error(message)
+}
