v3: Add QueryParser for get query using generic

ctx.go

@@ -1029,6 +1029,90 @@ func (c *DefaultCtx) QueryFloat(key string, defaultValue ...float64) float64 {
 	return value
 }
 
+// Query parses a query parameter value from the given context and returns it as the specified type.
+// The function supports parsing integers, booleans, floats, and strings.
+//
+// Default to empty or invalid key is 0.
+//
+//	GET /?name=alex&wanna_cake=2&id=
+//	Query[int]("wanna_cake", 1) == 2
+//	Query[int]("name", 1) == 1
+//	Query[int]("id", 1) == 1
+//	Query[int]("id") == 0
+//
+// Default to empty or invalid key is true.
+//
+//	Get /?name=alex&want_pizza=false&id=
+//	Query[bool]("want_pizza") == false
+//	Query[bool]("want_pizza", true) == false
+//	Query[bool]("name") == false
+//	Query[bool]("name", true) == true
+//	Query[bool]("id") == false
+//	Query[bool]("id", true) == true
+//
+// Default to empty or invalid key is 0.
+//
+//	GET /?name=alex&amount=32.23&id=
+//	Query[float64]("amount") = 32.23
+//	Query[float64]("amount", 3) = 32.23
+//	Query[float64]("name", 1) = 1
+//	Query[float64]("name") = 0
+//	Query[float64]("id", 3) = 3
+//
+// If the generic type is not written explicitly, the function will try to infer the type from the default value.
+// If the default value is not provided, the function will return the zero value of the type.
+//
+//	GET /?name=alex&wanna_cake=2&id=
+//	Query("wanna_cake", 1) == 2
+func Query[V string | bool | float64 | int](c Ctx, key string, defaultValue ...V) V {
+	ctx, ok := c.(*DefaultCtx)
+	if !ok {
+		panic("invalid context")
+	}
+	var v V
+	q := ctx.app.getString(ctx.fasthttp.QueryArgs().Peek(key))
+
+	switch any(v).(type) {
+	case int:
+		result, err := strconv.Atoi(q)
+		if err != nil {
+			if len(defaultValue) > 0 {
+				return defaultValue[0]
+			}
+			result = 0
+		}
+		return any(result).(V)
+	case float64:
+		result, err := strconv.ParseFloat(q, 64)
+		if err != nil {
+			if len(defaultValue) > 0 {
+				return defaultValue[0]
+			}
+			result = 0
+		}
+		return any(result).(V)
+	case bool:
+		result, err := strconv.ParseBool(q)
+		if err != nil {
+			if len(defaultValue) > 0 {
+				return defaultValue[0]
+			}
+			result = false
+		}
+		return any(result).(V)
+	case string:
+		if q == "" && len(defaultValue) > 0 {
+			return defaultValue[0]
+		}
+		return any(q).(V)
+	default:
+		if len(defaultValue) > 0 {
+			return defaultValue[0]
+		}
+		return v
+	}
+}
+
 // Range returns a struct containing the type and a slice of ranges.
 func (c *DefaultCtx) Range(size int) (Range, error) {
 	var rangeData Range

ctx_test.go

@@ -2092,6 +2092,20 @@ func Test_Ctx_QueryInt(t *testing.T) {
 	require.Equal(t, 2, c.QueryInt("id", 2))
 }
 
+func Test_Ctx_QueryParserInt(t *testing.T) {
+	t.Parallel()
+	app := New()
+	c := app.NewCtx(&fasthttp.RequestCtx{})
+
+	c.Request().URI().SetQueryString("search=john&age=20")
+	require.Equal(t, 0, Query[int](c, "foo"))
+	require.Equal(t, 20, Query[int](c, "age", 12))
+	require.Equal(t, 0, Query[int](c, "search"))
+	require.Equal(t, 1, Query[int](c, "search", 1))
+	require.Equal(t, 0, Query[int](c, "id"))
+	require.Equal(t, 2, Query[int](c, "id", 2))
+}
+
 func Test_Ctx_QueryBool(t *testing.T) {
 	t.Parallel()
 	app := New()
@@ -2107,6 +2121,21 @@ func Test_Ctx_QueryBool(t *testing.T) {
 	require.Equal(t, true, c.QueryBool("id", true))
 }
 
+func Test_Ctx_QueryParserBool(t *testing.T) {
+	t.Parallel()
+	app := New()
+	c := app.NewCtx(&fasthttp.RequestCtx{})
+
+	c.Request().URI().SetQueryString("name=alex&want_pizza=false&id=")
+
+	require.Equal(t, false, Query[bool](c, "want_pizza"))
+	require.Equal(t, false, Query[bool](c, "want_pizza", true))
+	require.Equal(t, false, Query[bool](c, "name"))
+	require.Equal(t, true, Query[bool](c, "name", true))
+	require.Equal(t, false, Query[bool](c, "id"))
+	require.Equal(t, true, Query[bool](c, "id", true))
+}
+
 func Test_Ctx_QueryFloat(t *testing.T) {
 	t.Parallel()
 	app := New()
@@ -2122,6 +2151,36 @@ func Test_Ctx_QueryFloat(t *testing.T) {
 	require.Equal(t, float64(0), c.QueryFloat("id"))
 }
 
+func Test_Ctx_QueryParserFloat(t *testing.T) {
+	t.Parallel()
+	app := New()
+	c := app.NewCtx(&fasthttp.RequestCtx{})
+
+	c.Request().URI().SetQueryString("name=alex&amount=32.23&id=")
+
+	require.Equal(t, 32.23, Query[float64](c, "amount"))
+	require.Equal(t, 32.23, Query[float64](c, "amount", 3.123))
+	require.Equal(t, 87.123, Query[float64](c, "name", 87.123))
+	require.Equal(t, float64(0), Query[float64](c, "name"))
+	require.Equal(t, 12.87, Query[float64](c, "id", 12.87))
+	require.Equal(t, float64(0), Query[float64](c, "id"))
+}
+
+func Test_Ctx_QueryParserString(t *testing.T) {
+	t.Parallel()
+	app := New()
+	c := app.NewCtx(&fasthttp.RequestCtx{})
+
+	c.Request().URI().SetQueryString("name=alex&amount=32.23&id=")
+
+	require.Equal(t, "alex", Query[string](c, "name"))
+	require.Equal(t, "alex", Query[string](c, "name", "john"))
+	require.Equal(t, "32.23", Query[string](c, "amount"))
+	require.Equal(t, "32.23", Query[string](c, "amount", "3.123"))
+	require.Equal(t, "", Query[string](c, "id"))
+	require.Equal(t, "12.87", Query[string](c, "id", "12.87"))
+}
+
 // go test -run Test_Ctx_Range
 func Test_Ctx_Range(t *testing.T) {
 	t.Parallel()