1 files changed, 86 insertions, 0 deletions
diff --git a/shortid_test.go b/shortid_test.go
new file mode 100644
index 0000000..54bc763
--- /dev/null
+++ b/shortid_test.go
@@ -0,0 +1,86 @@
+package main
+
+import "testing"
+
+func TestEncodeKnownValues(t *testing.T) {
+	tests := []struct {
+		id   int64
+		want string
+	}{
+		{0, "AAAA"},
+		{1, "AAAQ"},
+		{256, "AEAA"},
+		{65535, "777Q"},
+	}
+	for _, tt := range tests {
+		got, err := encodeID(tt.id)
+		if err != nil {
+			t.Fatalf("encodeID(%d): %v", tt.id, err)
+		}
+		if got != tt.want {
+			t.Errorf("encodeID(%d) = %q, want %q", tt.id, got, tt.want)
+		}
+	}
+}
+
+func TestDecodeKnownValues(t *testing.T) {
+	tests := []struct {
+		s    string
+		want int64
+	}{
+		{"AAAA", 0},
+		{"AAAQ", 1},
+		{"AEAA", 256},
+		{"777Q", 65535},
+	}
+	for _, tt := range tests {
+		got, err := decodeID(tt.s)
+		if err != nil {
+			t.Fatalf("decodeID(%q): %v", tt.s, err)
+		}
+		if got != tt.want {
+			t.Errorf("decodeID(%q) = %d, want %d", tt.s, got, tt.want)
+		}
+	}
+}
+
+func TestDecodeCaseInsensitive(t *testing.T) {
+	got, err := decodeID("aaaq")
+	if err != nil {
+		t.Fatalf("decodeID(aaaq): %v", err)
+	}
+	if got != 1 {
+		t.Errorf("decodeID(aaaq) = %d, want 1", got)
+	}
+}
+
+func TestRoundTrip(t *testing.T) {
+	for _, id := range []int64{0, 1, 100, 256, 1000, 65535, 100000, 1000000} {
+		s, err := encodeID(id)
+		if err != nil {
+			t.Fatalf("encodeID(%d): %v", id, err)
+		}
+		got, err := decodeID(s)
+		if err != nil {
+			t.Fatalf("decodeID(%q): %v", s, err)
+		}
+		if got != id {
+			t.Errorf("roundtrip(%d): got %d", id, got)
+		}
+	}
+}
+
+func TestEncodeOutOfRange(t *testing.T) {
+	if _, err := encodeID(-1); err == nil {
+		t.Error("encodeID(-1) should fail")
+	}
+}
+
+func TestDecodeInvalid(t *testing.T) {
+	invalids := []string{"", "A", "!!!!", "AAAAAA"}
+	for _, s := range invalids {
+		if _, err := decodeID(s); err == nil {
+			t.Errorf("decodeID(%q) should fail", s)
+		}
+	}
+}