From bcc267c2de5155b1921515c7e5d9781153b5218f Mon Sep 17 00:00:00 2001
From: Ben Schumacher <ben.schumacher@mattermost.com>
Date: Mon, 13 Nov 2023 14:28:27 +0100
Subject: [PATCH] Add type constraints for Map and Array fields (#43)

---
 .github/workflows/test.yml |  2 +-
 fieldapi.go                |  4 ++--
 fieldapi_test.go           | 25 +++++++++++++++++++++++++
 go.mod                     |  2 +-
 4 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 fieldapi_test.go

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d72f56d..094cf64 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -22,7 +22,7 @@ jobs:
     - name: Install Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.17.x
+        go-version: 1.18.x
 
     - name: Add dependencies
       run: |
diff --git a/fieldapi.go b/fieldapi.go
index 58b1228..d230035 100644
--- a/fieldapi.go
+++ b/fieldapi.go
@@ -100,11 +100,11 @@ func Millis(key string, val int64) Field {
 }
 
 // Array constructs a field containing a key and array value.
-func Array(key string, val interface{}) Field {
+func Array[S ~[]E, E any](key string, val S) Field {
 	return Field{Key: key, Type: ArrayType, Interface: val}
 }
 
 // Map constructs a field containing a key and map value.
-func Map(key string, val interface{}) Field {
+func Map[M ~map[K]V, K comparable, V any](key string, val M) Field {
 	return Field{Key: key, Type: MapType, Interface: val}
 }
diff --git a/fieldapi_test.go b/fieldapi_test.go
new file mode 100644
index 0000000..177c860
--- /dev/null
+++ b/fieldapi_test.go
@@ -0,0 +1,25 @@
+package logr
+
+import "testing"
+
+func TestFieldArray(t *testing.T) {
+	Array("array", []string{})
+	Array("array", []any{})
+
+	type myArray []any
+	Array("array", myArray{})
+
+	type myGenericArray[T any] []T
+	Array("array", myGenericArray[any]{})
+}
+
+func TestFieldMap(t *testing.T) {
+	Map("array", map[string]any{})
+	Map("array", map[int]any{})
+
+	type myMap map[string]string
+	Map("array", myMap{})
+
+	type myGenericMap[K comparable, V any] map[K]V
+	Map("array", myGenericMap[int, any]{})
+}
diff --git a/go.mod b/go.mod
index f5c0fde..ea4e0c0 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/mattermost/logr/v2
 
-go 1.17
+go 1.18
 
 require (
 	github.com/francoispqt/gojay v1.2.13