Improve error message for bad dependencies

src/index.ts

@@ -31,10 +31,16 @@ function getDependencies(funcs: unknown[]) {
   const dependencies = Array.isArray(funcs[0]) ? funcs[0] : funcs
 
   if (!dependencies.every(dep => typeof dep === 'function')) {
-    const dependencyTypes = dependencies.map(dep => typeof dep).join(', ')
+    const dependencyTypes = dependencies
+      .map(dep =>
+        typeof dep === 'function'
+          ? `function ${dep.name || 'unnamed'}()`
+          : typeof dep
+      )
+      .join(', ')
+
     throw new Error(
-      'Selector creators expect all input-selectors to be functions, ' +
-        `instead received the following types: [${dependencyTypes}]`
+      `createSelector expects all input-selectors to be functions, but received the following types: [${dependencyTypes}]`
     )
   }
 
@@ -76,7 +82,7 @@ export function createSelectorCreator<
 
     if (typeof resultFunc !== 'function') {
       throw new Error(
-        `createSelector expected an output function after the inputs, but received: [${typeof resultFunc}]`
+        `createSelector expects an output function after the inputs, but received: [${typeof resultFunc}]`
       )
     }
 

test/test_selector.ts

@@ -76,19 +76,24 @@ describe('Basic selector behavior', () => {
 
   test('basic selector invalid input selector', () => {
     expect(() =>
-      // @ts-ignore
       createSelector(
+        // @ts-ignore
         (state: StateAB) => state.a,
+        function input2(state: StateAB) {
+          return state.b
+        },
         'not a function',
         (a, b) => a + b
       )
-    ).toThrow(/input-selectors to be functions.*function, string/)
+    ).toThrow(
+      'createSelector expects all input-selectors to be functions, but received the following types: [function unnamed(), function input2(), string]'
+    )
 
     expect(() =>
       // @ts-ignore
       createSelector((state: StateAB) => state.a, 'not a function')
     ).toThrow(
-      'createSelector expected an output function after the inputs, but received: [string]'
+      'createSelector expects an output function after the inputs, but received: [string]'
     )
   })
 
@@ -662,7 +667,9 @@ describe('createStructureSelector', () => {
         // @ts-expect-error
         c: 'd'
       })
-    ).toThrow(/input-selectors to be functions.*function, string/)
+    ).toThrow(
+      'createSelector expects all input-selectors to be functions, but received the following types: [function a(), string]'
+    )
   })
 
   test('structured selector with custom selector creator', () => {