incurs_codemode/
program.rs

1use crate::{ConnectorDescription, generate_types, normalize_code};
2
3/// Adapter-specific settings for the shared Code Mode JavaScript harness.
4#[derive(Debug, Clone)]
5pub struct ProgramSourceOptions {
6    /// JavaScript expression that evaluates to the asynchronous dispatch function.
7    pub dispatch: String,
8    /// JavaScript expression exposed as `codemode.executionId`.
9    pub execution_id: String,
10    /// Optional JavaScript timer timeout for hosts that provide `setTimeout`.
11    pub timeout_ms: Option<u64>,
12}
13
14/// Builds the shared body used by local and remote Code Mode executors.
15pub fn build_program_source(
16    code: &str,
17    connectors: &[ConnectorDescription],
18    options: &ProgramSourceOptions,
19) -> Result<String, String> {
20    validate_names(connectors)?;
21    let code = normalize_code(code);
22    let bindings = connectors
23        .iter()
24        .map(|connector| {
25            let methods = connector
26                .tools
27                .iter()
28                .map(|tool| {
29                    format!(
30                        "{}: async (args = {{}}) => __unwrap(await __dispatch({{ kind: 'call', seq: __seq++, connector: {}, method: {}, arguments: __encode(args) }}))",
31                        serde_json::to_string(&tool.name).unwrap(),
32                        serde_json::to_string(&connector.name).unwrap(),
33                        serde_json::to_string(&tool.name).unwrap(),
34                    )
35                })
36                .collect::<Vec<_>>()
37                .join(",\n");
38            format!("const {} = {{\n{methods}\n}};", connector.name)
39        })
40        .collect::<Vec<_>>()
41        .join("\n");
42    let type_comment = connectors
43        .iter()
44        .map(generate_types)
45        .collect::<Vec<_>>()
46        .join("\n\n")
47        .replace("*/", "*\\/");
48    let run = if let Some(timeout_ms) = options.timeout_ms {
49        format!(
50            r#"await Promise.race([
51      __program(),
52      new Promise((_, reject) => setTimeout(() => reject(new Error("Code execution timed out after {timeout_ms}ms")), {timeout_ms}))
53    ])"#
54        )
55    } else {
56        "await __program()".to_string()
57    };
58    Ok(format!(
59        r#"/* Model-facing declarations:
60{type_comment}
61*/
62const __logs = [];
63let __seq = 0;
64const console = {{
65  log: (...values) => __logs.push(values.map(String).join(" ")),
66  info: (...values) => __logs.push(values.map(String).join(" ")),
67  warn: (...values) => __logs.push(values.map(String).join(" ")),
68  error: (...values) => __logs.push(values.map(String).join(" "))
69}};
70const __base64Encode = (value) => {{
71  const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
72  let result = "";
73  for (let index = 0; index < value.length; index += 3) {{
74    const first = value[index];
75    const second = value[index + 1];
76    const third = value[index + 2];
77    result += alphabet[first >> 2];
78    result += alphabet[((first & 3) << 4) | ((second ?? 0) >> 4)];
79    result += second === undefined ? "=" : alphabet[((second & 15) << 2) | ((third ?? 0) >> 6)];
80    result += third === undefined ? "=" : alphabet[third & 63];
81  }}
82  return result;
83}};
84const __base64Decode = (value) => {{
85  const alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
86  const clean = value.replace(/=+$/, "");
87  const bytes = [];
88  let buffer = 0;
89  let bits = 0;
90  for (const char of clean) {{
91    buffer = (buffer << 6) | alphabet.indexOf(char);
92    bits += 6;
93    if (bits >= 8) {{
94      bits -= 8;
95      bytes.push((buffer >> bits) & 255);
96    }}
97  }}
98  return new Uint8Array(bytes);
99}};
100const __encode = (value) => {{
101  if (value === undefined) return {{ __codemode_type: "undefined" }};
102  if (typeof value === "bigint") return {{ __codemode_type: "bigint", value: value.toString() }};
103  if (value instanceof Uint8Array) return {{ __codemode_type: "binary", value: __base64Encode(value) }};
104  if (Array.isArray(value)) return value.map(__encode);
105  if (value && typeof value === "object") {{
106    return Object.fromEntries(Object.entries(value).map(([key, child]) => [key, __encode(child)]));
107  }}
108  return value;
109}};
110const __decode = (value) => {{
111  if (Array.isArray(value)) return value.map(__decode);
112  if (value && typeof value === "object") {{
113    if (value.__codemode_type === "undefined") return undefined;
114    if (value.__codemode_type === "bigint") return BigInt(value.value);
115    if (value.__codemode_type === "binary") return __base64Decode(value.value);
116    return Object.fromEntries(Object.entries(value).map(([key, child]) => [key, __decode(child)]));
117  }}
118  return value;
119}};
120const __dispatch = {dispatch};
121const __unwrap = (response) => {{
122  if (response.__codemode_control__ === "pause") throw new Error("__CODEMODE_PAUSE__");
123  if (response.__codemode_control__ === "error") throw new Error(response.message);
124  return __decode(response.result);
125}};
126{bindings}
127const __callBuiltin = async (method, args) => __unwrap(await __dispatch({{
128  kind: "call",
129  seq: __seq++,
130  connector: "codemode",
131  method,
132  arguments: __encode(args)
133}}));
134const codemode = {{
135  executionId: {execution_id},
136  search: (query) => __callBuiltin("search", {{ query }}),
137  describe: (target) => __callBuiltin("describe", {{ target }}),
138  step: async (name, fn) => {{
139    const seq = __seq++;
140    const decision = await __dispatch({{ kind: "begin_step", seq, name }});
141    if (decision.kind === "pause") throw new Error("__CODEMODE_PAUSE__");
142    if (decision.kind === "replay") return __decode(decision.result);
143    const result = await fn();
144    await __dispatch({{ kind: "record_step", seq, result: __encode(result) }});
145    return result;
146  }}
147}};
148try {{
149  const __program = ({code});
150  const __result = {run};
151  return {{ result: __encode(__result), error: null, logs: __logs }};
152}} catch (error) {{
153  return {{
154    result: null,
155    error: error instanceof Error ? error.message : String(error),
156    logs: __logs
157  }};
158}}"#,
159        dispatch = options.dispatch,
160        execution_id = options.execution_id,
161    ))
162}
163
164fn validate_names(connectors: &[ConnectorDescription]) -> Result<(), String> {
165    const RESERVED: &[&str] = &[
166        "__incursDispatch",
167        "__dispatch",
168        "__encode",
169        "__decode",
170        "__unwrap",
171        "__seq",
172        "__logs",
173        "__program",
174        "__result",
175        "Promise",
176        "setTimeout",
177        "Error",
178        "console",
179        "codemode",
180        "fetch",
181    ];
182    let mut seen = std::collections::BTreeSet::new();
183    for connector in connectors {
184        if RESERVED.contains(&connector.name.as_str()) {
185            return Err(format!("Connector name \"{}\" is reserved", connector.name));
186        }
187        if !valid_identifier(&connector.name) {
188            return Err(format!(
189                "Connector name \"{}\" is not a valid JavaScript identifier",
190                connector.name
191            ));
192        }
193        if !seen.insert(&connector.name) {
194            return Err(format!("Duplicate connector name \"{}\"", connector.name));
195        }
196        let mut methods = std::collections::BTreeSet::new();
197        for tool in &connector.tools {
198            if !methods.insert(&tool.name) {
199                return Err(format!(
200                    "Duplicate tool name \"{}\" in connector \"{}\"",
201                    tool.name, connector.name
202                ));
203            }
204        }
205    }
206    Ok(())
207}
208
209fn valid_identifier(value: &str) -> bool {
210    let mut chars = value.chars();
211    chars
212        .next()
213        .is_some_and(|ch| ch == '_' || ch == '$' || ch.is_ascii_alphabetic())
214        && chars.all(|ch| ch == '_' || ch == '$' || ch.is_ascii_alphanumeric())
215}
216
217#[cfg(test)]
218mod tests {
219    use serde_json::json;
220
221    use crate::{ConnectorTool, ToolAnnotations};
222
223    use super::*;
224
225    #[test]
226    fn emits_shared_connector_and_step_harness() {
227        let source = build_program_source(
228            "state.read({ id: 1 })",
229            &[ConnectorDescription {
230                name: "state".to_string(),
231                instructions: None,
232                tools: vec![ConnectorTool {
233                    name: "read".to_string(),
234                    description: None,
235                    input_schema: json!({"type": "object"}),
236                    output_schema: None,
237                    instructions: None,
238                    examples: Vec::new(),
239                    annotations: ToolAnnotations::default(),
240                    policy: crate::ToolPolicy::default(),
241                }],
242            }],
243            &ProgramSourceOptions {
244                dispatch: "async (payload) => payload".to_string(),
245                execution_id: "\"test\"".to_string(),
246                timeout_ms: None,
247            },
248        )
249        .unwrap();
250
251        assert!(source.contains("const state"));
252        assert!(source.contains("const __dispatch = async (payload) => payload"));
253        assert!(source.contains("step: async (name, fn)"));
254    }
255}
incurs_codemode/program.rs

incurs_codemode/
program.rs
