authenticate: save oauth2 tokens to cache (#698)

Signed-off-by: Bobby DeSimone <bobbydesimone@gmail.com>

internal/hashutil/hashutil_test.go

@@ -0,0 +1,37 @@
+// Package hashutil provides NON-CRYPTOGRAPHIC utility functions for hashing
+package hashutil
+
+import "testing"
+
+func TestHash(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name string
+		v    interface{}
+		want uint64
+	}{
+		{"string", "string", 6134271061086542852},
+		{"num", 7, 609900476111905877},
+		{"compound struct", struct {
+			NESCarts      []string
+			numberOfCarts int
+		}{
+			[]string{"Battletoads", "Mega Man 1", "Clash at Demonhead"},
+			12,
+		},
+			9061978360207659575},
+		{"compound struct with embedded func (errors!)", struct {
+			AnswerToEverythingFn func() int
+		}{
+			func() int { return 42 },
+		},
+			0},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := Hash(tt.v); got != tt.want {
+				t.Errorf("Hash() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}