Remove duplicate types

Emyrk · Emyrk · commit 85e8b63238d7 · 2022-10-19T23:19:11.000-05:00
diff --git a/coderd/util/slice/slice.go b/coderd/util/slice/slice.go
@@ -22,6 +22,22 @@ func Overlap[T comparable](a []T, b []T) bool {
 	})
 }
 
+// Unique returns a new slice with all duplicate elements removed.
+// This is a slow function on large lists.
+// TODO: Sort elements and implement a faster search algorithm if we
+//
+//	really start to use this.
+func Unique[T comparable](a []T) []T {
+	cpy := make([]T, 0, len(a))
+	for _, v := range a {
+		v := v
+		if !Contains(cpy, v) {
+			cpy = append(cpy, v)
+		}
+	}
+	return cpy
+}
+
 func OverlapCompare[T any](a []T, b []T, equal func(a, b T) bool) bool {
 	// For each element in b, if at least 1 is contained in 'a',
 	// return true.
diff --git a/coderd/util/slice/slice_test.go b/coderd/util/slice/slice_test.go
@@ -9,6 +9,22 @@ import (
 	"github.com/coder/coder/coderd/util/slice"
 )
 
+func TestUnique(t *testing.T) {
+	t.Parallel()
+
+	require.ElementsMatch(t,
+		[]int{1, 2, 3, 4, 5},
+		slice.Unique([]int{
+			1, 2, 3, 4, 5, 1, 2, 3, 4, 5,
+		}))
+
+	require.ElementsMatch(t,
+		[]string{"a"},
+		slice.Unique([]string{
+			"a", "a", "a",
+		}))
+}
+
 func TestContains(t *testing.T) {
 	t.Parallel()
 
diff --git a/scripts/apitypings/main.go b/scripts/apitypings/main.go
@@ -13,6 +13,8 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/coder/coder/coderd/util/slice"
+
 	"github.com/fatih/structtag"
 	"golang.org/x/tools/go/packages"
 	"golang.org/x/xerrors"
@@ -316,6 +318,8 @@ func (g *Generator) buildUnion(obj types.Object, st *types.Union) (string, error
 		allTypes = append(allTypes, "null")
 	}
 
+	allTypes = slice.Unique(allTypes)
+
 	s.WriteString(fmt.Sprintf("export type %s = %s\n", obj.Name(), strings.Join(allTypes, " | ")))
 
 	return s.String(), nil
