feat(SEP-973): following change Icon.sizes from string to string array (#479)

Ref:
modelcontextprotocol/modelcontextprotocol#1531

Author: honsunrise

crates/rmcp/src/model.rs

@@ -713,9 +713,9 @@ pub struct Icon {
     /// Optional override if the server's MIME type is missing or generic
     #[serde(skip_serializing_if = "Option::is_none")]
     pub mime_type: Option<String>,
-    /// Size specification (e.g., "48x48", "any" for SVG, or "48x48 96x96")
+    /// Size specification, each string should be in WxH format (e.g., `\"48x48\"`, `\"96x96\"`) or `\"any\"` for scalable formats like SVG
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub sizes: Option<String>,
+    pub sizes: Option<Vec<String>>,
 }
 
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
@@ -2060,13 +2060,13 @@ mod tests {
         let icon = Icon {
             src: "https://example.com/icon.png".to_string(),
             mime_type: Some("image/png".to_string()),
-            sizes: Some("48x48".to_string()),
+            sizes: Some(vec!["48x48".to_string()]),
         };
 
         let json = serde_json::to_value(&icon).unwrap();
         assert_eq!(json["src"], "https://example.com/icon.png");
         assert_eq!(json["mimeType"], "image/png");
-        assert_eq!(json["sizes"], "48x48");
+        assert_eq!(json["sizes"][0], "48x48");
 
         // Test deserialization
         let deserialized: Icon = serde_json::from_value(json).unwrap();
@@ -2097,12 +2097,12 @@ mod tests {
                 Icon {
                     src: "https://example.com/icon.png".to_string(),
                     mime_type: Some("image/png".to_string()),
-                    sizes: Some("48x48".to_string()),
+                    sizes: Some(vec!["48x48".to_string()]),
                 },
                 Icon {
                     src: "https://example.com/icon.svg".to_string(),
                     mime_type: Some("image/svg+xml".to_string()),
-                    sizes: Some("any".to_string()),
+                    sizes: Some(vec!["any".to_string()]),
                 },
             ]),
             website_url: Some("https://example.com".to_string()),
@@ -2113,7 +2113,9 @@ mod tests {
         assert_eq!(json["websiteUrl"], "https://example.com");
         assert!(json["icons"].is_array());
         assert_eq!(json["icons"][0]["src"], "https://example.com/icon.png");
+        assert_eq!(json["icons"][0]["sizes"][0], "48x48");
         assert_eq!(json["icons"][1]["mimeType"], "image/svg+xml");
+        assert_eq!(json["icons"][1]["sizes"][0], "any");
     }
 
     #[test]
@@ -2143,7 +2145,7 @@ mod tests {
                 icons: Some(vec![Icon {
                     src: "https://example.com/server.png".to_string(),
                     mime_type: Some("image/png".to_string()),
-                    sizes: None,
+                    sizes: Some(vec!["48x48".to_string()]),
                 }]),
                 website_url: Some("https://docs.example.com".to_string()),
             },
@@ -2156,6 +2158,7 @@ mod tests {
             json["serverInfo"]["icons"][0]["src"],
             "https://example.com/server.png"
         );
+        assert_eq!(json["serverInfo"]["icons"][0]["sizes"][0], "48x48");
         assert_eq!(json["serverInfo"]["websiteUrl"], "https://docs.example.com");
     }
 }

crates/rmcp/tests/test_message_schema/client_json_rpc_message_schema.json

@@ -499,11 +499,14 @@
           ]
         },
         "sizes": {
-          "description": "Size specification (e.g., \"48x48\", \"any\" for SVG, or \"48x48 96x96\")",
+          "description": "Size specification, each string should be in WxH format (e.g., `\\\"48x48\\\"`, `\\\"96x96\\\"`) or `\\\"any\\\"` for scalable formats like SVG",
           "type": [
-            "string",
+            "array",
             "null"
-          ]
+          ],
+          "items": {
+            "type": "string"
+          }
         },
         "src": {
           "description": "A standard URI pointing to an icon resource",

crates/rmcp/tests/test_message_schema/client_json_rpc_message_schema_current.json

@@ -499,11 +499,14 @@
           ]
         },
         "sizes": {
-          "description": "Size specification (e.g., \"48x48\", \"any\" for SVG, or \"48x48 96x96\")",
+          "description": "Size specification, each string should be in WxH format (e.g., `\\\"48x48\\\"`, `\\\"96x96\\\"`) or `\\\"any\\\"` for scalable formats like SVG",
           "type": [
-            "string",
+            "array",
             "null"
-          ]
+          ],
+          "items": {
+            "type": "string"
+          }
         },
         "src": {
           "description": "A standard URI pointing to an icon resource",

crates/rmcp/tests/test_message_schema/server_json_rpc_message_schema.json

@@ -630,11 +630,14 @@
           ]
         },
         "sizes": {
-          "description": "Size specification (e.g., \"48x48\", \"any\" for SVG, or \"48x48 96x96\")",
+          "description": "Size specification, each string should be in WxH format (e.g., `\\\"48x48\\\"`, `\\\"96x96\\\"`) or `\\\"any\\\"` for scalable formats like SVG",
           "type": [
-            "string",
+            "array",
             "null"
-          ]
+          ],
+          "items": {
+            "type": "string"
+          }
         },
         "src": {
           "description": "A standard URI pointing to an icon resource",

crates/rmcp/tests/test_message_schema/server_json_rpc_message_schema_current.json

@@ -630,11 +630,14 @@
           ]
         },
         "sizes": {
-          "description": "Size specification (e.g., \"48x48\", \"any\" for SVG, or \"48x48 96x96\")",
+          "description": "Size specification, each string should be in WxH format (e.g., `\\\"48x48\\\"`, `\\\"96x96\\\"`) or `\\\"any\\\"` for scalable formats like SVG",
           "type": [
-            "string",
+            "array",
             "null"
-          ]
+          ],
+          "items": {
+            "type": "string"
+          }
         },
         "src": {
           "description": "A standard URI pointing to an icon resource",

examples/simple-chat-client/Cargo.toml

@@ -19,5 +19,5 @@ rmcp = { workspace = true, features = [
     "transport-child-process",
     "transport-sse-client-reqwest",
     "transport-streamable-http-client-reqwest"
-], no-default-features = true }
+] }
 clap = { version = "4.0", features = ["derive"] }