feat(rewriter): add redirect(), get_cookie(), add_cookie() methods to rule engine (#36)

internal/rule/http/request_test.go

@@ -2,6 +2,7 @@ package http
 
 import (
 	"context"
+	"fmt"
 	"net/http"
 	"testing"
 
@@ -185,6 +186,134 @@ func TestDelRequestHeaders(t *testing.T) {
 	}
 }
 
+func TestAddRequestCookie(t *testing.T) {
+	type TestCase struct {
+		Cookie     map[string]any
+		Check      func(t *testing.T, tc TestCase, req *http.Request)
+		ShouldFail bool
+	}
+
+	testCases := []TestCase{
+		{
+			Cookie: map[string]any{
+				"name": "test",
+			},
+			Check: func(t *testing.T, tc TestCase, req *http.Request) {
+				cookie, err := req.Cookie(tc.Cookie["name"].(string))
+				if err != nil {
+					t.Errorf("%+v", errors.WithStack(err))
+					return
+				}
+
+				if e, g := tc.Cookie["name"], cookie.Name; e != g {
+					t.Errorf("cookie.Name: expected '%v', got '%v'", e, g)
+				}
+			},
+		},
+		{
+			Cookie: map[string]any{
+				"name":  "foo",
+				"value": "test",
+			},
+			Check: func(t *testing.T, tc TestCase, req *http.Request) {
+				cookie, err := req.Cookie(tc.Cookie["name"].(string))
+				if err != nil {
+					t.Errorf("%+v", errors.WithStack(err))
+					return
+				}
+
+				if e, g := tc.Cookie["name"], cookie.Name; e != g {
+					t.Errorf("cookie.Name: expected '%v', got '%v'", e, g)
+				}
+
+				if e, g := tc.Cookie["value"], cookie.Value; e != g {
+					t.Errorf("cookie.Value: expected '%v', got '%v'", e, g)
+				}
+			},
+		},
+	}
+
+	for idx, tc := range testCases {
+		t.Run(fmt.Sprintf("Case_%d", idx), func(t *testing.T) {
+			type Vars struct {
+				NewCookie map[string]any `expr:"new_cookie"`
+			}
+
+			engine := createRuleEngine[Vars](t,
+				rule.WithExpr(addRequestCookieFunc()),
+				rule.WithRules(
+					`add_cookie(ctx, vars.new_cookie)`,
+				),
+			)
+
+			req, err := http.NewRequest("GET", "http://example.net", nil)
+			if err != nil {
+				t.Fatalf("%+v", errors.WithStack(err))
+			}
+
+			vars := Vars{
+				NewCookie: tc.Cookie,
+			}
+
+			ctx := context.Background()
+			ctx = WithRequest(ctx, req)
+
+			if _, err := engine.Apply(ctx, vars); err != nil {
+				t.Fatalf("%+v", errors.WithStack(err))
+			}
+
+			if tc.ShouldFail {
+				t.Error("engine.Apply() should have failed")
+			}
+
+			if tc.Check != nil {
+				tc.Check(t, tc, req)
+			}
+		})
+	}
+}
+
+func TestGetRequestCookie(t *testing.T) {
+	type Vars struct {
+		CookieName string `expr:"cookieName"`
+	}
+
+	engine := createRuleEngine[Vars](t,
+		rule.WithExpr(getRequestCookieFunc()),
+		rule.WithRules(
+			"let cookie = get_cookie(ctx, vars.cookieName); cookie.value",
+		),
+	)
+
+	req, err := http.NewRequest("GET", "http://example.net", nil)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	vars := Vars{
+		CookieName: "foo",
+	}
+
+	cookie := &http.Cookie{
+		Name:  vars.CookieName,
+		Value: "bar",
+	}
+
+	req.AddCookie(cookie)
+
+	ctx := context.Background()
+	ctx = WithRequest(ctx, req)
+
+	results, err := engine.Apply(ctx, vars)
+	if err != nil {
+		t.Fatalf("%+v", errors.WithStack(err))
+	}
+
+	if e, g := cookie.Value, results[0]; e != g {
+		t.Errorf("result[0]: expected '%v', got '%v'", e, g)
+	}
+}
+
 func createRuleEngine[V any](t *testing.T, funcs ...rule.OptionFunc) *rule.Engine[V] {
 	engine, err := rule.NewEngine[V](funcs...)
 	if err != nil {