mockforge_core/
conditions.rs

1//! Condition evaluation system for override rules
2//!
3//! This module provides support for conditional application of overrides based on
4//! JSONPath and XPath queries, as well as other conditional expressions.
5
6use jsonpath::Selector;
7use roxmltree::{Document, Node};
8use serde_json::Value;
9use std::collections::HashMap;
10use thiserror::Error;
11
12/// Errors that can occur during condition evaluation
13#[derive(Debug, Error)]
14pub enum ConditionError {
15    /// JSONPath expression is invalid or cannot be parsed
16    #[error("Invalid JSONPath expression: {0}")]
17    InvalidJsonPath(String),
18
19    /// XPath expression is invalid or cannot be parsed
20    #[error("Invalid XPath expression: {0}")]
21    InvalidXPath(String),
22
23    /// XML document is malformed or cannot be parsed
24    #[error("Invalid XML: {0}")]
25    InvalidXml(String),
26
27    /// Condition type is not supported by the evaluator
28    #[error("Unsupported condition type: {0}")]
29    UnsupportedCondition(String),
30
31    /// General condition evaluation failure with error message
32    #[error("Condition evaluation failed: {0}")]
33    EvaluationFailed(String),
34}
35
36/// Context for evaluating conditions
37#[derive(Debug, Clone)]
38pub struct ConditionContext {
39    /// Request body (JSON)
40    pub request_body: Option<Value>,
41    /// Response body (JSON)
42    pub response_body: Option<Value>,
43    /// Request body as XML string
44    pub request_xml: Option<String>,
45    /// Response body as XML string
46    pub response_xml: Option<String>,
47    /// Request headers
48    pub headers: HashMap<String, String>,
49    /// Query parameters
50    pub query_params: HashMap<String, String>,
51    /// Request path
52    pub path: String,
53    /// HTTP method
54    pub method: String,
55    /// Operation ID
56    pub operation_id: Option<String>,
57    /// Tags
58    pub tags: Vec<String>,
59}
60
61impl Default for ConditionContext {
62    fn default() -> Self {
63        Self::new()
64    }
65}
66
67impl ConditionContext {
68    /// Create a new empty condition context
69    pub fn new() -> Self {
70        Self {
71            request_body: None,
72            response_body: None,
73            request_xml: None,
74            response_xml: None,
75            headers: HashMap::new(),
76            query_params: HashMap::new(),
77            path: String::new(),
78            method: String::new(),
79            operation_id: None,
80            tags: Vec::new(),
81        }
82    }
83
84    /// Set the request body as JSON
85    pub fn with_request_body(mut self, body: Value) -> Self {
86        self.request_body = Some(body);
87        self
88    }
89
90    /// Set the response body as JSON
91    pub fn with_response_body(mut self, body: Value) -> Self {
92        self.response_body = Some(body);
93        self
94    }
95
96    /// Set the request body as XML string
97    pub fn with_request_xml(mut self, xml: String) -> Self {
98        self.request_xml = Some(xml);
99        self
100    }
101
102    /// Set the response body as XML string
103    pub fn with_response_xml(mut self, xml: String) -> Self {
104        self.response_xml = Some(xml);
105        self
106    }
107
108    /// Set the request headers
109    pub fn with_headers(mut self, headers: HashMap<String, String>) -> Self {
110        self.headers = headers;
111        self
112    }
113
114    /// Set the query parameters
115    pub fn with_query_params(mut self, params: HashMap<String, String>) -> Self {
116        self.query_params = params;
117        self
118    }
119
120    /// Set the request path
121    pub fn with_path(mut self, path: String) -> Self {
122        self.path = path;
123        self
124    }
125
126    /// Set the HTTP method
127    pub fn with_method(mut self, method: String) -> Self {
128        self.method = method;
129        self
130    }
131
132    /// Set the OpenAPI operation ID
133    pub fn with_operation_id(mut self, operation_id: String) -> Self {
134        self.operation_id = Some(operation_id);
135        self
136    }
137
138    /// Set the OpenAPI tags
139    pub fn with_tags(mut self, tags: Vec<String>) -> Self {
140        self.tags = tags;
141        self
142    }
143}
144
145/// Evaluate a condition expression
146pub fn evaluate_condition(
147    condition: &str,
148    context: &ConditionContext,
149) -> Result<bool, ConditionError> {
150    let condition = condition.trim();
151
152    if condition.is_empty() {
153        return Ok(true); // Empty condition always evaluates to true
154    }
155
156    // Handle logical operators
157    if let Some(and_conditions) = condition.strip_prefix("AND(") {
158        if let Some(inner) = and_conditions.strip_suffix(")") {
159            return evaluate_and_condition(inner, context);
160        }
161    }
162
163    if let Some(or_conditions) = condition.strip_prefix("OR(") {
164        if let Some(inner) = or_conditions.strip_suffix(")") {
165            return evaluate_or_condition(inner, context);
166        }
167    }
168
169    if let Some(not_condition) = condition.strip_prefix("NOT(") {
170        if let Some(inner) = not_condition.strip_suffix(")") {
171            return evaluate_not_condition(inner, context);
172        }
173    }
174
175    // Handle JSONPath queries
176    if condition.starts_with("$.") || condition.starts_with("$[") {
177        return evaluate_jsonpath(condition, context);
178    }
179
180    // Handle XPath queries
181    if condition.starts_with("/") || condition.starts_with("//") {
182        return evaluate_xpath(condition, context);
183    }
184
185    // Handle simple comparisons
186    evaluate_simple_condition(condition, context)
187}
188
189/// Evaluate AND condition with multiple sub-conditions
190fn evaluate_and_condition(
191    conditions: &str,
192    context: &ConditionContext,
193) -> Result<bool, ConditionError> {
194    let parts: Vec<&str> = conditions.split(',').map(|s| s.trim()).collect();
195
196    for part in parts {
197        if !evaluate_condition(part, context)? {
198            return Ok(false);
199        }
200    }
201
202    Ok(true)
203}
204
205/// Evaluate OR condition with multiple sub-conditions
206fn evaluate_or_condition(
207    conditions: &str,
208    context: &ConditionContext,
209) -> Result<bool, ConditionError> {
210    let parts: Vec<&str> = conditions.split(',').map(|s| s.trim()).collect();
211
212    for part in parts {
213        if evaluate_condition(part, context)? {
214            return Ok(true);
215        }
216    }
217
218    Ok(false)
219}
220
221/// Evaluate NOT condition
222fn evaluate_not_condition(
223    condition: &str,
224    context: &ConditionContext,
225) -> Result<bool, ConditionError> {
226    Ok(!evaluate_condition(condition, context)?)
227}
228
229/// Evaluate JSONPath query
230fn evaluate_jsonpath(query: &str, context: &ConditionContext) -> Result<bool, ConditionError> {
231    // Determine if this is a request or response query
232    let (_is_request, json_value) = if query.starts_with("$.request.") {
233        let _query = query.replace("$.request.", "$.");
234        (true, &context.request_body)
235    } else if query.starts_with("$.response.") {
236        let _query = query.replace("$.response.", "$.");
237        (false, &context.response_body)
238    } else {
239        // Default to response body if available, otherwise request body
240        if context.response_body.is_some() {
241            (false, &context.response_body)
242        } else {
243            (true, &context.request_body)
244        }
245    };
246
247    let Some(json_value) = json_value else {
248        return Ok(false); // No body to query
249    };
250
251    match Selector::new(query) {
252        Ok(selector) => {
253            let results: Vec<_> = selector.find(json_value).collect();
254            Ok(!results.is_empty())
255        }
256        Err(_) => Err(ConditionError::InvalidJsonPath(query.to_string())),
257    }
258}
259
260/// Evaluate XPath query
261fn evaluate_xpath(query: &str, context: &ConditionContext) -> Result<bool, ConditionError> {
262    // Determine if this is a request or response query
263    let (_is_request, xml_content) = if query.starts_with("/request/") {
264        let _query = query.replace("/request/", "/");
265        (true, &context.request_xml)
266    } else if query.starts_with("/response/") {
267        let _query = query.replace("/response/", "/");
268        (false, &context.response_xml)
269    } else {
270        // Default to response XML if not specified
271        (false, &context.response_xml)
272    };
273
274    let Some(xml_content) = xml_content else {
275        println!("Debug - No XML content available for query: {}", query);
276        return Ok(false); // No XML content to query
277    };
278
279    println!("Debug - Evaluating XPath '{}' against XML content: {}", query, xml_content);
280
281    match Document::parse(xml_content) {
282        Ok(doc) => {
283            // Simple XPath evaluation - check if any nodes match
284            let root = doc.root_element();
285            println!("Debug - XML root element: {}", root.tag_name().name());
286            let matches = evaluate_xpath_simple(&root, query);
287            println!("Debug - XPath result: {}", matches);
288            Ok(matches)
289        }
290        Err(e) => {
291            println!("Debug - Failed to parse XML: {}", e);
292            Err(ConditionError::InvalidXml(xml_content.clone()))
293        }
294    }
295}
296
297/// Simple XPath evaluator (basic implementation)
298fn evaluate_xpath_simple(node: &Node, xpath: &str) -> bool {
299    // This is a simplified XPath implementation
300    // For production use, consider a more complete XPath library
301
302    // Handle descendant-or-self axis: //element (check this FIRST before stripping //)
303    if let Some(element_name) = xpath.strip_prefix("//") {
304        println!(
305            "Debug - Checking descendant-or-self for element '{}' on node '{}'",
306            element_name,
307            node.tag_name().name()
308        );
309        if node.tag_name().name() == element_name {
310            println!("Debug - Found match: {} == {}", node.tag_name().name(), element_name);
311            return true;
312        }
313        // Check descendants
314        for child in node.children() {
315            if child.is_element() {
316                println!("Debug - Checking child element: {}", child.tag_name().name());
317                if evaluate_xpath_simple(&child, &format!("//{}", element_name)) {
318                    return true;
319                }
320            }
321        }
322        return false; // If no descendant found, return false
323    }
324
325    let xpath = xpath.trim_start_matches('/');
326
327    if xpath.is_empty() {
328        return true;
329    }
330
331    // Handle attribute queries: element[@attribute='value']
332    if let Some((element_part, attr_part)) = xpath.split_once('[') {
333        if let Some(attr_query) = attr_part.strip_suffix(']') {
334            if let Some((attr_name, attr_value)) = attr_query.split_once("='") {
335                if let Some(expected_value) = attr_value.strip_suffix('\'') {
336                    if let Some(attr_val) = attr_name.strip_prefix('@') {
337                        if node.tag_name().name() == element_part {
338                            if let Some(attr) = node.attribute(attr_val) {
339                                return attr == expected_value;
340                            }
341                        }
342                    }
343                }
344            }
345        }
346        return false;
347    }
348
349    // Handle element name matching with optional predicates
350    if let Some((element_name, rest)) = xpath.split_once('/') {
351        if node.tag_name().name() == element_name {
352            if rest.is_empty() {
353                return true;
354            }
355            // Check child elements recursively
356            for child in node.children() {
357                if child.is_element() && evaluate_xpath_simple(&child, rest) {
358                    return true;
359                }
360            }
361        }
362    } else if node.tag_name().name() == xpath {
363        return true;
364    }
365
366    // Handle text content queries: element/text()
367    if let Some(text_query) = xpath.strip_suffix("/text()") {
368        if node.tag_name().name() == text_query {
369            return node.text().is_some_and(|t| !t.trim().is_empty());
370        }
371    }
372
373    false
374}
375
376/// Evaluate simple conditions like header checks, query param checks, etc.
377fn evaluate_simple_condition(
378    condition: &str,
379    context: &ConditionContext,
380) -> Result<bool, ConditionError> {
381    // Handle header conditions: header[name]=value or header[name]!=value
382    if let Some(header_condition) = condition.strip_prefix("header[") {
383        if let Some((header_name, rest)) = header_condition.split_once("]") {
384            // Headers are stored in lowercase in the context
385            let header_name_lower = header_name.to_lowercase();
386            let rest_trimmed = rest.trim();
387            // Check for != operator (with optional whitespace)
388            if let Some(expected_value) = rest_trimmed.strip_prefix("!=") {
389                let expected_value = expected_value.trim().trim_matches('\'').trim_matches('"');
390                if let Some(actual_value) = context.headers.get(&header_name_lower) {
391                    // Header exists: return true if actual value != expected value
392                    return Ok(actual_value != expected_value);
393                }
394                // Header doesn't exist: return true if checking != '' (empty string)
395                // because non-existent header is not equal to empty string
396                return Ok(expected_value.is_empty());
397            }
398            // Check for = operator (with optional whitespace)
399            if let Some(expected_value) = rest_trimmed.strip_prefix("=") {
400                let expected_value = expected_value.trim().trim_matches('\'').trim_matches('"');
401                if let Some(actual_value) = context.headers.get(&header_name_lower) {
402                    return Ok(actual_value == expected_value);
403                }
404                return Ok(false);
405            }
406        }
407    }
408
409    // Handle query parameter conditions: query[name]=value or query[name]==value
410    if let Some(query_condition) = condition.strip_prefix("query[") {
411        if let Some((param_name, rest)) = query_condition.split_once("]") {
412            let rest_trimmed = rest.trim();
413            // Check for == operator (with optional whitespace and quotes)
414            if let Some(expected_value) = rest_trimmed.strip_prefix("==") {
415                let expected_value = expected_value.trim().trim_matches('\'').trim_matches('"');
416                if let Some(actual_value) = context.query_params.get(param_name) {
417                    return Ok(actual_value == expected_value);
418                }
419                return Ok(false);
420            }
421            // Check for = operator (with optional whitespace)
422            if let Some(expected_value) = rest_trimmed.strip_prefix("=") {
423                let expected_value = expected_value.trim();
424                if let Some(actual_value) = context.query_params.get(param_name) {
425                    return Ok(actual_value == expected_value);
426                }
427                return Ok(false);
428            }
429        }
430    }
431
432    // Handle method conditions: method=POST
433    if let Some(method_condition) = condition.strip_prefix("method=") {
434        return Ok(context.method == method_condition);
435    }
436
437    // Handle path conditions: path=/api/users
438    if let Some(path_condition) = condition.strip_prefix("path=") {
439        return Ok(context.path == path_condition);
440    }
441
442    // Handle tag conditions: has_tag[admin]
443    if let Some(tag_condition) = condition.strip_prefix("has_tag[") {
444        if let Some(tag) = tag_condition.strip_suffix("]") {
445            return Ok(context.tags.contains(&tag.to_string()));
446        }
447    }
448
449    // Handle operation conditions: operation=getUser
450    if let Some(op_condition) = condition.strip_prefix("operation=") {
451        if let Some(operation_id) = &context.operation_id {
452            return Ok(operation_id == op_condition);
453        }
454        return Ok(false);
455    }
456
457    Err(ConditionError::UnsupportedCondition(condition.to_string()))
458}
459
460#[cfg(test)]
461mod tests {
462    use super::*;
463    use serde_json::json;
464
465    #[test]
466    fn test_jsonpath_condition() {
467        let context = ConditionContext::new().with_response_body(json!({
468            "user": {
469                "name": "John",
470                "role": "admin"
471            },
472            "items": [1, 2, 3]
473        }));
474
475        // Test simple path existence
476        assert!(evaluate_condition("$.user", &context).unwrap());
477
478        // Test specific value matching
479        assert!(evaluate_condition("$.user.role", &context).unwrap());
480
481        // Test array access
482        assert!(evaluate_condition("$.items[0]", &context).unwrap());
483
484        // Test non-existent path
485        assert!(!evaluate_condition("$.nonexistent", &context).unwrap());
486    }
487
488    #[test]
489    fn test_simple_conditions() {
490        let mut headers = HashMap::new();
491        headers.insert("authorization".to_string(), "Bearer token123".to_string());
492
493        let mut query_params = HashMap::new();
494        query_params.insert("limit".to_string(), "10".to_string());
495
496        let context = ConditionContext::new()
497            .with_headers(headers)
498            .with_query_params(query_params)
499            .with_method("POST".to_string())
500            .with_path("/api/users".to_string());
501
502        // Test header condition
503        assert!(evaluate_condition("header[authorization]=Bearer token123", &context).unwrap());
504        assert!(!evaluate_condition("header[authorization]=Bearer wrong", &context).unwrap());
505
506        // Test query parameter condition
507        assert!(evaluate_condition("query[limit]=10", &context).unwrap());
508        assert!(!evaluate_condition("query[limit]=20", &context).unwrap());
509
510        // Test method condition
511        assert!(evaluate_condition("method=POST", &context).unwrap());
512        assert!(!evaluate_condition("method=GET", &context).unwrap());
513
514        // Test path condition
515        assert!(evaluate_condition("path=/api/users", &context).unwrap());
516        assert!(!evaluate_condition("path=/api/posts", &context).unwrap());
517    }
518
519    #[test]
520    fn test_logical_conditions() {
521        let context = ConditionContext::new()
522            .with_method("POST".to_string())
523            .with_path("/api/users".to_string());
524
525        // Test AND condition
526        assert!(evaluate_condition("AND(method=POST,path=/api/users)", &context).unwrap());
527        assert!(!evaluate_condition("AND(method=GET,path=/api/users)", &context).unwrap());
528
529        // Test OR condition
530        assert!(evaluate_condition("OR(method=POST,path=/api/posts)", &context).unwrap());
531        assert!(!evaluate_condition("OR(method=GET,path=/api/posts)", &context).unwrap());
532
533        // Test NOT condition
534        assert!(!evaluate_condition("NOT(method=POST)", &context).unwrap());
535        assert!(evaluate_condition("NOT(method=GET)", &context).unwrap());
536    }
537
538    #[test]
539    fn test_xpath_condition() {
540        let xml_content = r#"
541            <user id="123">
542                <name>John Doe</name>
543                <role>admin</role>
544                <preferences>
545                    <theme>dark</theme>
546                    <notifications>true</notifications>
547                </preferences>
548            </user>
549        "#;
550
551        let context = ConditionContext::new().with_response_xml(xml_content.to_string());
552
553        // Test basic element existence
554        assert!(evaluate_condition("/user", &context).unwrap());
555
556        // Test nested element
557        assert!(evaluate_condition("/user/name", &context).unwrap());
558
559        // Test attribute query
560        assert!(evaluate_condition("/user[@id='123']", &context).unwrap());
561        assert!(!evaluate_condition("/user[@id='456']", &context).unwrap());
562
563        // Test text content
564        assert!(evaluate_condition("/user/name/text()", &context).unwrap());
565
566        // Test descendant axis
567        assert!(evaluate_condition("//theme", &context).unwrap());
568
569        // Test non-existent element
570        assert!(!evaluate_condition("/nonexistent", &context).unwrap());
571    }
572}
mockforge_core/conditions.rs

mockforge_core/
conditions.rs
