github_copilot_sdk/
tool.rs

1//! Typed tool definition framework.
2//!
3//! Provides the [`ToolHandler`](crate::tool::ToolHandler) trait for
4//! implementing tools as named types. Attach a handler to a
5//! [`Tool`](crate::types::Tool) via
6//! [`Tool::with_handler`](crate::types::Tool::with_handler), then install
7//! the resulting tools on a session via
8//! [`SessionConfig::with_tools`](crate::types::SessionConfig::with_tools).
9//! The SDK builds an internal name-keyed registry from the handlers and
10//! dispatches to the matching handler when the CLI broadcasts
11//! `external_tool.requested`.
12//!
13//! Enable the `derive` feature for `schema_for`, which generates JSON
14//! Schema from Rust types via `schemars`.
15
16use std::collections::HashMap;
17
18use async_trait::async_trait;
19/// Re-export of [`schemars::JsonSchema`] for deriving tool parameter schemas.
20#[cfg(feature = "derive")]
21pub use schemars::JsonSchema;
22
23use crate::Error;
24#[cfg(any(feature = "derive", test))]
25use crate::types::Tool;
26use crate::types::{ToolBinaryResult, ToolInvocation, ToolResult, ToolResultExpanded};
27
28/// Generate a JSON Schema [`Value`](serde_json::Value) from a Rust type.
29///
30/// Strips `$schema` and `title` root-level metadata so the output is ready
31/// to use as [`Tool::parameters`].
32///
33/// # Example
34///
35/// ```rust
36/// use github_copilot_sdk::tool::{schema_for, JsonSchema};
37///
38/// #[derive(JsonSchema)]
39/// struct Params {
40///     /// City name
41///     city: String,
42/// }
43///
44/// let schema = schema_for::<Params>();
45/// assert_eq!(schema["type"], "object");
46/// assert!(schema["properties"]["city"].is_object());
47/// ```
48#[cfg(feature = "derive")]
49pub fn schema_for<T: schemars::JsonSchema>() -> serde_json::Value {
50    let schema = schemars::schema_for!(T);
51    let mut value = serde_json::to_value(schema).expect("JSON Schema serialization cannot fail");
52    if let Some(obj) = value.as_object_mut() {
53        obj.remove("$schema");
54        obj.remove("title");
55    }
56    value
57}
58
59/// Convert a JSON Schema [`Value`](serde_json::Value) into the
60/// [`Tool::parameters`](crate::types::Tool::parameters) map shape
61/// expected by the protocol.
62///
63/// Panics if the input is not a JSON object — tool parameter schemas
64/// are always top-level objects (`{"type": "object", ...}`). Pair with
65/// `schema_for` (available with the `derive` feature) or a
66/// `serde_json::json!(...)` literal.
67///
68/// Use [`try_tool_parameters`] when the schema comes from dynamic input and
69/// should return a recoverable error instead of panicking.
70///
71/// # Example
72///
73/// ```rust
74/// use github_copilot_sdk::tool::tool_parameters;
75/// use github_copilot_sdk::Tool;
76///
77/// let mut tool = Tool::default();
78/// tool.name = "ping".to_string();
79/// tool.description = "ping the server".to_string();
80/// tool.parameters = tool_parameters(serde_json::json!({"type": "object"}));
81/// # let _ = tool;
82/// ```
83pub fn tool_parameters(schema: serde_json::Value) -> HashMap<String, serde_json::Value> {
84    try_tool_parameters(schema).expect("tool parameter schema must be a JSON object")
85}
86
87/// Fallible variant of [`tool_parameters`] for callers handling dynamic schema input.
88pub fn try_tool_parameters(
89    schema: serde_json::Value,
90) -> Result<HashMap<String, serde_json::Value>, serde_json::Error> {
91    serde_json::from_value(schema)
92}
93
94/// Convert an MCP `CallToolResult` JSON value into a Copilot tool result.
95///
96/// Returns `None` when the value is not shaped like a `CallToolResult`.
97pub fn convert_mcp_call_tool_result(value: &serde_json::Value) -> Option<ToolResult> {
98    let content = value.get("content")?.as_array()?;
99    let mut text_parts = Vec::new();
100    let mut binary_results = Vec::new();
101
102    for block in content {
103        match block.get("type").and_then(serde_json::Value::as_str) {
104            Some("text") => {
105                if let Some(text) = block.get("text").and_then(serde_json::Value::as_str) {
106                    text_parts.push(text.to_string());
107                }
108            }
109            Some("image") => {
110                let data = block
111                    .get("data")
112                    .and_then(serde_json::Value::as_str)
113                    .filter(|s| !s.is_empty());
114                let mime_type = block
115                    .get("mimeType")
116                    .and_then(serde_json::Value::as_str)
117                    .filter(|s| !s.is_empty());
118                if let (Some(data), Some(mime_type)) = (data, mime_type) {
119                    binary_results.push(ToolBinaryResult {
120                        data: data.to_string(),
121                        mime_type: mime_type.to_string(),
122                        r#type: "image".to_string(),
123                        description: None,
124                    });
125                }
126            }
127            Some("resource") => {
128                let Some(resource) = block.get("resource").and_then(serde_json::Value::as_object)
129                else {
130                    continue;
131                };
132                if let Some(text) = resource
133                    .get("text")
134                    .and_then(serde_json::Value::as_str)
135                    .filter(|s| !s.is_empty())
136                {
137                    text_parts.push(text.to_string());
138                }
139                if let Some(blob) = resource
140                    .get("blob")
141                    .and_then(serde_json::Value::as_str)
142                    .filter(|s| !s.is_empty())
143                {
144                    let mime_type = resource
145                        .get("mimeType")
146                        .and_then(serde_json::Value::as_str)
147                        .filter(|s| !s.is_empty())
148                        .unwrap_or("application/octet-stream");
149                    let description = resource
150                        .get("uri")
151                        .and_then(serde_json::Value::as_str)
152                        .filter(|s| !s.is_empty())
153                        .map(ToString::to_string);
154                    binary_results.push(ToolBinaryResult {
155                        data: blob.to_string(),
156                        mime_type: mime_type.to_string(),
157                        r#type: "resource".to_string(),
158                        description,
159                    });
160                }
161            }
162            _ => {}
163        }
164    }
165
166    Some(ToolResult::Expanded(ToolResultExpanded {
167        text_result_for_llm: text_parts.join("\n"),
168        result_type: if value.get("isError").and_then(serde_json::Value::as_bool) == Some(true) {
169            "failure".to_string()
170        } else {
171            "success".to_string()
172        },
173        binary_results_for_llm: (!binary_results.is_empty()).then_some(binary_results),
174        session_log: None,
175        error: None,
176        tool_telemetry: None,
177    }))
178}
179
180/// A client-defined tool's runtime implementation.
181///
182/// Implement this trait when you want to bind a Rust function to a tool
183/// name and have the SDK dispatch matching `external_tool.requested`
184/// broadcasts to it. Attach the impl to a [`Tool`](crate::types::Tool)
185/// via [`Tool::with_handler`](crate::types::Tool::with_handler).
186///
187/// Named handler types (e.g. `struct MyTool;`) are visible in stack
188/// traces and navigable via "go to definition", which is preferable to
189/// closure-based alternatives for non-trivial tools. For trivial tools,
190/// the `define_tool` helper function (available with the `derive`
191/// feature) wraps a free `async fn` or closure into a [`Tool`](crate::types::Tool) with
192/// the handler already attached.
193///
194/// # Example
195///
196/// ```rust,ignore
197/// use github_copilot_sdk::tool::{schema_for, JsonSchema, ToolHandler};
198/// use github_copilot_sdk::types::{Tool, ToolInvocation};
199/// use github_copilot_sdk::{Error, ToolResult};
200/// use serde::Deserialize;
201/// use async_trait::async_trait;
202/// use std::sync::Arc;
203///
204/// #[derive(Deserialize, JsonSchema)]
205/// struct GetWeatherParams {
206///     /// City name
207///     city: String,
208/// }
209///
210/// struct GetWeather;
211///
212/// #[async_trait]
213/// impl ToolHandler for GetWeather {
214///     async fn call(&self, inv: ToolInvocation) -> Result<ToolResult, Error> {
215///         let params: GetWeatherParams = serde_json::from_value(inv.arguments)?;
216///         Ok(ToolResult::Text(format!("Weather in {}: sunny", params.city)))
217///     }
218/// }
219///
220/// // Build the Tool declaration with the handler attached:
221/// let tool = Tool::new("get_weather")
222///     .with_description("Get weather for a city")
223///     .with_parameters(schema_for::<GetWeatherParams>())
224///     .with_handler(Arc::new(GetWeather));
225/// ```
226#[async_trait]
227pub trait ToolHandler: Send + Sync + 'static {
228    /// Handle a tool invocation from the agent.
229    async fn call(&self, invocation: ToolInvocation) -> Result<ToolResult, Error>;
230}
231
232/// Define a [`Tool`] from an async function (or closure) that takes a typed,
233/// `JsonSchema`-derived parameter struct.
234///
235/// The returned [`Tool`] carries an attached handler ready to install on a
236/// session via [`SessionConfig::with_tools`](crate::types::SessionConfig::with_tools).
237/// JSON Schema for the parameter type is generated via [`schema_for`] at
238/// construction time.
239///
240/// The handler bound (`Fn(ToolInvocation, P) -> Fut + Send + Sync + 'static`)
241/// accepts both bare `async fn` items and closures — the same shape as
242/// [`tower::service_fn`][tower-service-fn] and
243/// [`hyper::service::service_fn`][hyper-service-fn]. Prefer a free `async fn`
244/// for non-trivial tools so it shows up in stack traces by name.
245///
246/// The closure receives the full [`ToolInvocation`] alongside the deserialized
247/// parameters so handlers can use `inv.session_id`, `inv.tool_call_id`, or
248/// other invocation metadata. Handlers that don't need that metadata can
249/// destructure with `|_inv, params|`.
250///
251/// # Example
252///
253/// ```rust,no_run
254/// use github_copilot_sdk::tool::{define_tool, JsonSchema};
255/// use github_copilot_sdk::types::ToolInvocation;
256/// use github_copilot_sdk::{Error, ToolResult};
257/// use serde::Deserialize;
258///
259/// #[derive(Deserialize, JsonSchema)]
260/// struct GetWeatherParams {
261///     /// City name
262///     city: String,
263/// }
264///
265/// async fn get_weather(
266///     inv: ToolInvocation,
267///     params: GetWeatherParams,
268/// ) -> Result<ToolResult, Error> {
269///     let _ = inv.session_id;
270///     Ok(ToolResult::Text(format!("Sunny in {}", params.city)))
271/// }
272///
273/// // Pass a free async fn — preferred for non-trivial tools.
274/// let tool = define_tool("get_weather", "Get weather for a city", get_weather);
275///
276/// // ...or an inline closure when the body is trivial.
277/// let tool = define_tool(
278///     "echo",
279///     "Echo the input",
280///     |_inv, params: GetWeatherParams| async move {
281///         Ok(ToolResult::Text(params.city))
282///     },
283/// );
284/// # let _ = tool;
285/// ```
286///
287/// [tower-service-fn]: https://docs.rs/tower/latest/tower/fn.service_fn.html
288/// [hyper-service-fn]: https://docs.rs/hyper/latest/hyper/service/fn.service_fn.html
289#[cfg(feature = "derive")]
290pub fn define_tool<P, F, Fut>(
291    name: impl Into<String>,
292    description: impl Into<String>,
293    handler: F,
294) -> Tool
295where
296    P: schemars::JsonSchema + serde::de::DeserializeOwned + Send + 'static,
297    F: Fn(ToolInvocation, P) -> Fut + Send + Sync + 'static,
298    Fut: std::future::Future<Output = Result<ToolResult, Error>> + Send + 'static,
299{
300    struct FnHandler<P, F> {
301        handler: F,
302        _marker: std::marker::PhantomData<fn(P)>,
303    }
304
305    #[async_trait]
306    impl<P, F, Fut> ToolHandler for FnHandler<P, F>
307    where
308        P: schemars::JsonSchema + serde::de::DeserializeOwned + Send + 'static,
309        F: Fn(ToolInvocation, P) -> Fut + Send + Sync + 'static,
310        Fut: std::future::Future<Output = Result<ToolResult, Error>> + Send + 'static,
311    {
312        async fn call(&self, mut invocation: ToolInvocation) -> Result<ToolResult, Error> {
313            let arguments = std::mem::take(&mut invocation.arguments);
314            let params: P = serde_json::from_value(arguments)?;
315            (self.handler)(invocation, params).await
316        }
317    }
318
319    Tool {
320        name: name.into(),
321        description: description.into(),
322        parameters: tool_parameters(schema_for::<P>()),
323        ..Default::default()
324    }
325    .with_handler(std::sync::Arc::new(FnHandler {
326        handler,
327        _marker: std::marker::PhantomData,
328    }))
329}
330
331/// Define a declaration-only [`Tool`] with a JSON Schema derived from `P`.
332///
333/// Equivalent to [`define_tool`] but produces a [`Tool`] with no attached
334/// handler — useful when another connected client services this tool, or
335/// when you only need to advertise the schema for capability negotiation.
336///
337/// # Example
338///
339/// ```rust,no_run
340/// use github_copilot_sdk::tool::{define_tool_declaration, JsonSchema};
341/// use serde::Deserialize;
342///
343/// #[derive(Deserialize, JsonSchema)]
344/// struct Params { query: String }
345///
346/// let declared = define_tool_declaration::<Params>(
347///     "legacy_thing",
348///     "Handled by another connected client",
349/// );
350/// # let _ = declared;
351/// ```
352#[cfg(feature = "derive")]
353pub fn define_tool_declaration<P>(name: impl Into<String>, description: impl Into<String>) -> Tool
354where
355    P: schemars::JsonSchema,
356{
357    Tool {
358        name: name.into(),
359        description: description.into(),
360        parameters: tool_parameters(schema_for::<P>()),
361        ..Default::default()
362    }
363}
364
365#[cfg(test)]
366mod tests {
367    use super::*;
368    use crate::types::SessionId;
369
370    struct EchoTool;
371
372    fn echo_tool() -> Tool {
373        Tool {
374            name: "echo".to_string(),
375            description: "Echo the input".to_string(),
376            parameters: tool_parameters(serde_json::json!({"type": "object"})),
377            ..Default::default()
378        }
379        .with_handler(std::sync::Arc::new(EchoTool))
380    }
381
382    #[async_trait]
383    impl ToolHandler for EchoTool {
384        async fn call(&self, inv: ToolInvocation) -> Result<ToolResult, Error> {
385            Ok(ToolResult::Text(inv.arguments.to_string()))
386        }
387    }
388
389    #[test]
390    fn tool_handler_returns_tool_definition() {
391        let def = echo_tool();
392        assert_eq!(def.name, "echo");
393        assert_eq!(def.description, "Echo the input");
394        assert!(def.parameters.contains_key("type"));
395        assert!(def.handler.is_some());
396    }
397
398    #[test]
399    fn try_tool_parameters_rejects_non_object_schema() {
400        let err = try_tool_parameters(serde_json::json!(["not", "an", "object"]))
401            .expect_err("non-object schemas should be rejected");
402
403        assert!(err.is_data());
404    }
405
406    #[test]
407    fn convert_mcp_call_tool_result_collects_text_and_binary_content() {
408        let result = convert_mcp_call_tool_result(&serde_json::json!({
409            "isError": true,
410            "content": [
411                { "type": "text", "text": "hello" },
412                { "type": "image", "data": "aW1n", "mimeType": "image/png" },
413                {
414                    "type": "resource",
415                    "resource": {
416                        "uri": "file:///tmp/data.bin",
417                        "blob": "Ymlu",
418                        "mimeType": "application/octet-stream",
419                        "text": "resource text"
420                    }
421                }
422            ]
423        }))
424        .expect("valid CallToolResult should convert");
425
426        let ToolResult::Expanded(expanded) = result else {
427            panic!("expected expanded tool result");
428        };
429
430        assert_eq!(expanded.text_result_for_llm, "hello\nresource text");
431        assert_eq!(expanded.result_type, "failure");
432        let binary_results = expanded
433            .binary_results_for_llm
434            .expect("binary results should be captured");
435        assert_eq!(binary_results.len(), 2);
436        assert_eq!(binary_results[0].r#type, "image");
437        assert_eq!(binary_results[0].data, "aW1n");
438        assert_eq!(binary_results[0].mime_type, "image/png");
439        assert_eq!(
440            binary_results[1].description.as_deref(),
441            Some("file:///tmp/data.bin")
442        );
443    }
444
445    #[test]
446    fn convert_mcp_call_tool_result_converts_image_content() {
447        let result = convert_mcp_call_tool_result(&serde_json::json!({
448            "content": [
449                { "type": "image", "data": "aW1hZ2U=", "mimeType": "image/jpeg" }
450            ]
451        }))
452        .expect("valid CallToolResult should convert");
453
454        let ToolResult::Expanded(expanded) = result else {
455            panic!("expected expanded tool result");
456        };
457
458        assert_eq!(expanded.text_result_for_llm, "");
459        assert_eq!(expanded.result_type, "success");
460        let binary_results = expanded
461            .binary_results_for_llm
462            .expect("image result should be captured");
463        assert_eq!(binary_results.len(), 1);
464        assert_eq!(binary_results[0].data, "aW1hZ2U=");
465        assert_eq!(binary_results[0].mime_type, "image/jpeg");
466        assert_eq!(binary_results[0].r#type, "image");
467        assert!(binary_results[0].description.is_none());
468    }
469
470    #[test]
471    fn convert_mcp_call_tool_result_converts_resource_blob_content() {
472        let result = convert_mcp_call_tool_result(&serde_json::json!({
473            "content": [
474                {
475                    "type": "resource",
476                    "resource": {
477                        "uri": "file:///tmp/report.pdf",
478                        "blob": "cGRm",
479                        "mimeType": "application/pdf"
480                    }
481                }
482            ]
483        }))
484        .expect("valid CallToolResult should convert");
485
486        let ToolResult::Expanded(expanded) = result else {
487            panic!("expected expanded tool result");
488        };
489
490        let binary_results = expanded
491            .binary_results_for_llm
492            .expect("resource result should be captured");
493        assert_eq!(binary_results.len(), 1);
494        assert_eq!(binary_results[0].data, "cGRm");
495        assert_eq!(binary_results[0].mime_type, "application/pdf");
496        assert_eq!(binary_results[0].r#type, "resource");
497        assert_eq!(
498            binary_results[0].description.as_deref(),
499            Some("file:///tmp/report.pdf")
500        );
501    }
502
503    #[test]
504    fn convert_mcp_call_tool_result_defaults_resource_blob_mime_type() {
505        let result = convert_mcp_call_tool_result(&serde_json::json!({
506            "content": [
507                {
508                    "type": "resource",
509                    "resource": {
510                        "uri": "file:///tmp/data.bin",
511                        "blob": "Ymlu"
512                    }
513                },
514                {
515                    "type": "resource",
516                    "resource": {
517                        "blob": "YmluMg==",
518                        "mimeType": ""
519                    }
520                }
521            ]
522        }))
523        .expect("valid CallToolResult should convert");
524
525        let ToolResult::Expanded(expanded) = result else {
526            panic!("expected expanded tool result");
527        };
528
529        let binary_results = expanded
530            .binary_results_for_llm
531            .expect("resource blobs should be captured");
532        assert_eq!(binary_results.len(), 2);
533        assert_eq!(binary_results[0].mime_type, "application/octet-stream");
534        assert_eq!(binary_results[1].mime_type, "application/octet-stream");
535    }
536
537    #[test]
538    fn convert_mcp_call_tool_result_omits_binary_results_without_binary_content() {
539        let result = convert_mcp_call_tool_result(&serde_json::json!({
540            "content": [
541                { "type": "text", "text": "hello" },
542                {
543                    "type": "resource",
544                    "resource": {
545                        "uri": "file:///tmp/readme.md",
546                        "text": "resource text"
547                    }
548                }
549            ]
550        }))
551        .expect("valid CallToolResult should convert");
552
553        let ToolResult::Expanded(expanded) = result else {
554            panic!("expected expanded tool result");
555        };
556
557        assert_eq!(expanded.text_result_for_llm, "hello\nresource text");
558        assert!(expanded.binary_results_for_llm.is_none());
559    }
560
561    #[tokio::test]
562    async fn tool_handler_call_returns_result() {
563        let tool = EchoTool;
564        let inv = ToolInvocation {
565            session_id: SessionId::from("s1"),
566            tool_call_id: "tc1".to_string(),
567            tool_name: "echo".to_string(),
568            arguments: serde_json::json!({"msg": "hello"}),
569            traceparent: None,
570            tracestate: None,
571        };
572
573        let result = tool.call(inv).await.unwrap();
574        match result {
575            ToolResult::Text(s) => assert!(s.contains("hello")),
576            _ => panic!("expected Text result"),
577        }
578    }
579
580    #[cfg(feature = "derive")]
581    #[tokio::test]
582    async fn define_tool_builds_schema_and_dispatches() {
583        use serde::Deserialize;
584
585        #[derive(Deserialize, schemars::JsonSchema)]
586        struct Params {
587            city: String,
588        }
589
590        let tool = define_tool(
591            "weather",
592            "Get the weather for a city",
593            |_inv, params: Params| async move {
594                Ok(ToolResult::Text(format!("sunny in {}", params.city)))
595            },
596        );
597
598        assert_eq!(tool.name, "weather");
599        assert_eq!(tool.description, "Get the weather for a city");
600        assert_eq!(tool.parameters["type"], "object");
601        assert!(tool.parameters["properties"]["city"].is_object());
602        let handler = tool.handler.as_ref().expect("define_tool attaches handler");
603
604        let inv = ToolInvocation {
605            session_id: SessionId::from("s1"),
606            tool_call_id: "tc1".to_string(),
607            tool_name: "weather".to_string(),
608            arguments: serde_json::json!({"city": "Seattle"}),
609            traceparent: None,
610            tracestate: None,
611        };
612        match handler.call(inv).await.unwrap() {
613            ToolResult::Text(s) => assert_eq!(s, "sunny in Seattle"),
614            _ => panic!("expected Text result"),
615        }
616    }
617
618    // Tests requiring `schemars` (the `derive` feature).
619    #[cfg(feature = "derive")]
620    mod derive_tests {
621        use serde::Deserialize;
622
623        use super::super::*;
624        use crate::{ErrorKind, SessionId};
625
626        #[derive(Deserialize, schemars::JsonSchema)]
627        struct GetWeatherParams {
628            /// City name to get weather for.
629            city: String,
630            /// Temperature unit (celsius or fahrenheit).
631            unit: Option<String>,
632        }
633
634        #[test]
635        fn schema_for_generates_clean_schema() {
636            let schema = schema_for::<GetWeatherParams>();
637            assert_eq!(schema["type"], "object");
638            assert!(schema["properties"]["city"].is_object());
639            assert!(schema["properties"]["unit"].is_object());
640            // city is required (non-Option), unit is not
641            let required = schema["required"].as_array().unwrap();
642            assert!(required.contains(&serde_json::json!("city")));
643            assert!(!required.contains(&serde_json::json!("unit")));
644            // Root-level metadata stripped
645            assert!(schema.get("$schema").is_none());
646            assert!(schema.get("title").is_none());
647        }
648
649        struct GetWeatherTool;
650
651        fn get_weather_tool() -> Tool {
652            Tool {
653                name: "get_weather".to_string(),
654                description: "Get weather for a city".to_string(),
655                parameters: tool_parameters(schema_for::<GetWeatherParams>()),
656                ..Default::default()
657            }
658            .with_handler(std::sync::Arc::new(GetWeatherTool))
659        }
660
661        #[async_trait]
662        impl ToolHandler for GetWeatherTool {
663            async fn call(&self, inv: ToolInvocation) -> Result<ToolResult, Error> {
664                let params: GetWeatherParams = serde_json::from_value(inv.arguments)?;
665                Ok(ToolResult::Text(format!(
666                    "{} {}",
667                    params.city,
668                    params.unit.unwrap_or_default()
669                )))
670            }
671        }
672
673        #[test]
674        fn tool_handler_with_schema_for() {
675            let def = get_weather_tool();
676            assert_eq!(def.name, "get_weather");
677            let schema = serde_json::to_value(&def.parameters).expect("serialize tool parameters");
678            assert_eq!(schema["type"], "object");
679            assert!(schema["properties"]["city"].is_object());
680            assert!(def.handler.is_some());
681        }
682
683        #[tokio::test]
684        async fn tool_handler_deserializes_typed_params() {
685            let tool = GetWeatherTool;
686            let inv = ToolInvocation {
687                session_id: SessionId::from("s1"),
688                tool_call_id: "tc1".to_string(),
689                tool_name: "get_weather".to_string(),
690                arguments: serde_json::json!({"city": "Seattle", "unit": "celsius"}),
691                traceparent: None,
692                tracestate: None,
693            };
694
695            let result = tool.call(inv).await.unwrap();
696            match result {
697                ToolResult::Text(s) => assert_eq!(s, "Seattle celsius"),
698                _ => panic!("expected Text result"),
699            }
700        }
701
702        #[tokio::test]
703        async fn tool_handler_returns_error_on_bad_params() {
704            let tool = GetWeatherTool;
705            let inv = ToolInvocation {
706                session_id: SessionId::from("s1"),
707                tool_call_id: "tc1".to_string(),
708                tool_name: "get_weather".to_string(),
709                arguments: serde_json::json!({"wrong_field": 42}),
710                traceparent: None,
711                tracestate: None,
712            };
713
714            let err = tool.call(inv).await.unwrap_err();
715            assert!(matches!(err.kind(), ErrorKind::Json));
716        }
717
718        #[tokio::test]
719        async fn schema_for_derived_tool_round_trips_through_call() {
720            let tool = GetWeatherTool;
721
722            // Calling the tool with matching arguments returns the
723            // expected typed result. (Per-name dispatch is the SDK's
724            // concern; here we exercise just the handler contract.)
725            let result = tool
726                .call(ToolInvocation {
727                    session_id: SessionId::from("s1"),
728                    tool_call_id: "tc1".to_string(),
729                    tool_name: "get_weather".to_string(),
730                    arguments: serde_json::json!({"city": "Portland"}),
731                    traceparent: None,
732                    tracestate: None,
733                })
734                .await
735                .expect("ToolHandler::call should succeed for matching args");
736            match result {
737                ToolResult::Text(s) => assert!(s.contains("Portland")),
738                _ => panic!("expected ToolResult::Text"),
739            }
740        }
741    }
742}
github_copilot_sdk/tool.rs

github_copilot_sdk/
tool.rs
