Makes Link.Param() no longer return an error

main.go

@@ -23,20 +23,20 @@ func (l Link) HasParam(key string) bool {
 	return false
 }
 
-// Param returns the value of a parameter, or an error on failure
+// Param returns the value of a parameter if it exists
-func (l Link) Param(key string) (string, error) {
+func (l Link) Param(key string) string {
 	for k, v := range l.Params {
 		if key == k {
-			return v, nil
+			return v
 		}
 	}
-	return "", fmt.Errorf("Could not find param '%s'", key)
+	return ""
 }
 
 // String returns the string representation of a link
 func (l Link) String() string {
 
-	p := make([]string, len(l.Params))
+	p := make([]string, 0, len(l.Params))
 	for k, v := range l.Params {
 		p = append(p, fmt.Sprintf("%s=\"%s\"", k, v))
 	}

main_test.go

@@ -51,17 +51,14 @@ func TestLinkMethods(t *testing.T) {
 		t.Errorf("Link should not have param 'foo'")
 	}
 
-	val, err := link.Param("pet")
+	val := link.Param("pet")
-	if err != nil {
-		t.Errorf("Error value should be nil")
-	}
 	if val != "cat" {
 		t.Errorf("Link should have param pet=\"cat\"")
 	}
 
-	_, err = link.Param("foo")
+	val = link.Param("foo")
-	if err == nil {
+	if val != "" {
-		t.Errorf("Error value should not be nil")
+		t.Errorf("Link should not have value for param 'foo'")
 	}
 
 }
@@ -108,15 +105,13 @@ func TestLinkToString(t *testing.T) {
 	l := Link{
 		URL: "http://example.com/page/2",
 		Rel: "next",
+		Params: map[string]string{
+			"foo": "bar",
+		},
 	}
 
 	have := l.String()
 
-	want := "<http://example.com/page/2>; rel=\"next\""
-	if have != want {
-		t.Errorf("Want `%s`; have `%s`", want, have)
-	}
-
 	parsed := Parse(have)
 
 	if len(parsed) != 1 {
@@ -130,6 +125,10 @@ func TestLinkToString(t *testing.T) {
 	if parsed[0].Rel != l.Rel {
 		t.Errorf("Re-parsed link header should have matching rel, but has `%s`", parsed[0].Rel)
 	}
+
+	if parsed[0].Param("foo") != "bar" {
+		t.Errorf("Re-parsed link header should have foo=\"bar\" but doesn't")
+	}
 }
 
 func TestLinksToString(t *testing.T) {