fix(subsonic): clearing playlist comment and public in Subsonic API (#4258)

* fix(subsonic): allow clearing playlist comment

* fix(playlists): simplify comment and public parameter handling

Signed-off-by: Deluan <deluan@navidrome.org>

* refactor(playlists): streamline fakePlaylists implementation in tests

Signed-off-by: Deluan <deluan@navidrome.org>

---------

Signed-off-by: Deluan <deluan@navidrome.org>

utils/req/req.go

@@ -35,6 +35,25 @@ func (r *Values) String(param string) (string, error) {
 	return v, nil
 }
 
+func (r *Values) StringPtr(param string) *string {
+	var v *string
+	if _, exists := r.URL.Query()[param]; exists {
+		s := r.URL.Query().Get(param)
+		v = &s
+	}
+	return v
+}
+
+func (r *Values) BoolPtr(param string) *bool {
+	var v *bool
+	if _, exists := r.URL.Query()[param]; exists {
+		s := r.URL.Query().Get(param)
+		b := strings.Contains("/true/on/1/", "/"+strings.ToLower(s)+"/")
+		v = &b
+	}
+	return v
+}
+
 func (r *Values) StringOr(param, def string) string {
 	v, _ := r.String(param)
 	if v == "" {

utils/req/req_test.go

@@ -219,4 +219,59 @@ var _ = Describe("Request Helpers", func() {
 			})
 		})
 	})
+
+	Describe("ParamStringPtr", func() {
+		BeforeEach(func() {
+			r = req.Params(httptest.NewRequest("GET", "/ping?a=123", nil))
+		})
+
+		It("returns pointer to string if param exists", func() {
+			ptr := r.StringPtr("a")
+			Expect(ptr).ToNot(BeNil())
+			Expect(*ptr).To(Equal("123"))
+		})
+
+		It("returns nil if param does not exist", func() {
+			ptr := r.StringPtr("xx")
+			Expect(ptr).To(BeNil())
+		})
+
+		It("returns pointer to empty string if param exists but is empty", func() {
+			r = req.Params(httptest.NewRequest("GET", "/ping?a=", nil))
+			ptr := r.StringPtr("a")
+			Expect(ptr).ToNot(BeNil())
+			Expect(*ptr).To(Equal(""))
+		})
+	})
+
+	Describe("ParamBoolPtr", func() {
+		Context("value is true", func() {
+			BeforeEach(func() {
+				r = req.Params(httptest.NewRequest("GET", "/ping?b=true", nil))
+			})
+
+			It("returns pointer to true if param is 'true'", func() {
+				ptr := r.BoolPtr("b")
+				Expect(ptr).ToNot(BeNil())
+				Expect(*ptr).To(BeTrue())
+			})
+		})
+
+		Context("value is false", func() {
+			BeforeEach(func() {
+				r = req.Params(httptest.NewRequest("GET", "/ping?b=false", nil))
+			})
+
+			It("returns pointer to false if param is 'false'", func() {
+				ptr := r.BoolPtr("b")
+				Expect(ptr).ToNot(BeNil())
+				Expect(*ptr).To(BeFalse())
+			})
+		})
+
+		It("returns nil if param does not exist", func() {
+			ptr := r.BoolPtr("xx")
+			Expect(ptr).To(BeNil())
+		})
+	})
 })