From 1a47b61b4f1382b8672804e6e3f8909a09520907 Mon Sep 17 00:00:00 2001
From: AdamMagued <adammagued@users.noreply.github.com>
Date: Fri, 2 Oct 2026 15:12:29 +0000
Subject: [PATCH] feat: support arbitrary slices and arrays in ToSlice

In ToSliceE, only []any and []map[string]any were explicitly handled in the type switch. When callers passed typed slices (such as []int, []string, or slices of custom structs) or fixed-size arrays, ToSliceE returned an error unable to cast to []any.

Use reflection to inspect reflect.Slice and reflect.Array inputs, allocating a []any slice of corresponding length and converting each indexed element via Interface(). Add regression tests covering []int, []string, arrays, and struct slices.

Fixes #355
---
 slice.go      | 14 ++++++++++++++
 slice_test.go |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/slice.go b/slice.go
index e6a8328c..c1e1f0d7 100644
--- a/slice.go
+++ b/slice.go
@@ -17,6 +17,10 @@ func ToSliceE(i any) ([]any, error) {
 
 	var s []any
 
+	if i == nil {
+		return s, fmt.Errorf(errorMsg, i, i, s)
+	}
+
 	switch v := i.(type) {
 	case []any:
 		// TODO: use slices.Clone
@@ -28,6 +32,16 @@ func ToSliceE(i any) ([]any, error) {
 
 		return s, nil
 	default:
+		kind := reflect.TypeOf(i).Kind()
+		if kind == reflect.Slice || kind == reflect.Array {
+			rv := reflect.ValueOf(i)
+			out := make([]any, rv.Len())
+			for idx := 0; idx < rv.Len(); idx++ {
+				out[idx] = rv.Index(idx).Interface()
+			}
+			return out, nil
+		}
+
 		return s, fmt.Errorf(errorMsg, i, i, s)
 	}
 }
diff --git a/slice_test.go b/slice_test.go
index fb7597cc..57b5c58e 100644
--- a/slice_test.go
+++ b/slice_test.go
@@ -230,9 +230,18 @@ func TestUintSlice(t *testing.T) {
 }
 
 func TestSlice(t *testing.T) {
+	type user struct {
+		Name string
+	}
+
 	testCases := []testCase{
 		{[]any{1, 3}, []any{1, 3}, false},
 		{[]map[string]any{{"k1": 1}, {"k2": 2}}, []any{map[string]any{"k1": 1}, map[string]any{"k2": 2}}, false},
+		{[]int{1, 2, 3}, []any{1, 2, 3}, false},
+		{[]string{"a", "b"}, []any{"a", "b"}, false},
+		{[3]int{1, 2, 3}, []any{1, 2, 3}, false},
+		{[2]string{"a", "b"}, []any{"a", "b"}, false},
+		{[]user{{"alice"}, {"bob"}}, []any{user{"alice"}, user{"bob"}}, false},
 
 		// Failure cases
 		{nil, nil, true},