Added Timeout and length check for pattern matching

Author: ashishrp-aws

plugins/amazonq/chat/jetbrains-community/tst/software/aws/toolkits/jetbrains/services/amazonqFeatureDev/FeatureDevSessionContextTest.kt

@@ -85,7 +85,7 @@ class FeatureDevSessionContextTest : FeatureDevTestBase(HeavyJavaCodeInsightTest
             "settings.gradle",
             "build.gradle",
             "gradle/wrapper/gradle-wrapper.properties",
-            "builder/GetTestBuilder.java", //check for false positives
+            "builder/GetTestBuilder.java", // check for false positives
             ".aws-sam/build/function1",
             ".gem/specs.rb",
             "archive.zip",

plugins/core/jetbrains-community/src/software/aws/toolkits/jetbrains/services/amazonq/FeatureDevSessionContext.kt

@@ -15,6 +15,7 @@ import kotlinx.coroutines.flow.channelFlow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
+import kotlinx.coroutines.withTimeout
 import org.apache.commons.codec.digest.DigestUtils
 import org.apache.commons.io.FileUtils
 import software.aws.toolkits.jetbrains.core.coroutines.getCoroutineBgContext
@@ -97,7 +98,7 @@ class FeatureDevSessionContext(val project: Project, val maxProjectSizeBytes: Lo
                 addAll(additionalGitIgnoreRules.map { convertGitIgnorePatternToRegex(it) })
                 addAll(parseGitIgnore())
             }.mapNotNull { pattern ->
-                runCatching { Regex(pattern) }.getOrNull()
+                runCatching { pattern?.let { Regex(it) } }.getOrNull()
             }
         } catch (e: Exception) {
             emptyList()
@@ -136,7 +137,13 @@ class FeatureDevSessionContext(val project: Project, val maxProjectSizeBytes: Lo
                 // entries against them by adding a trailing /.
                 // TODO: Add unit tests for gitignore matching
                 val relative = if (path.startsWith(projectRootPath.toString())) Paths.get(path).relativeTo(projectRootPath) else path
-                async { pattern.matches("$relative/") }
+                async {
+                    try {
+                        withTimeout(REGEX_TIMEOUT_MS) { pattern.matches("$relative/") }
+                    } catch (e: Exception) {
+                        false
+                    }
+                }
             }
         }
 
@@ -240,7 +247,7 @@ class FeatureDevSessionContext(val project: Project, val maxProjectSizeBytes: Lo
         tempFilePath
     }
 
-    private fun parseGitIgnore(): Set<String> {
+    private fun parseGitIgnore(): Set<String?> {
         if (!gitIgnoreFile.exists()) {
             return emptySet()
         }
@@ -252,46 +259,57 @@ class FeatureDevSessionContext(val project: Project, val maxProjectSizeBytes: Lo
     }
 
     // gitignore patterns are not regex, method update needed.
-    fun convertGitIgnorePatternToRegex(pattern: String): String = pattern
-        // Escape special regex characters except * and ?
-        .replace(".", "\\.")
-        .replace("+", "\\+")
-        .replace("(", "\\(")
-        .replace(")", "\\)")
-        .replace("[", "\\[")
-        .replace("]", "\\]")
-        .replace("{", "\\{")
-        .replace("}", "\\}")
-        .replace(",", "\\,")
-        .replace("^", "\\^")
-        .replace("$", "\\$")
-        .replace("|", "\\|")
-        // Convert gitignore glob patterns to regex
-        .replace("**", ".*?") // Match any directory depth
-        .replace("*", "[^/]*?") // Match any character except path separator
-        .replace("?", "[^/]") // Match single character except path separator
-        .let { pattern ->
-            when {
-                // If pattern starts with '/', anchor it to the start of the path
-                pattern.startsWith("/") -> "^${pattern.substring(1)}"
-                // If pattern doesn't start with '/', it can match anywhere in the path
-                else -> "(?:^|.*/?)$pattern"
-            }
+    fun convertGitIgnorePatternToRegex(pattern: String): String? {
+        // Skip invalid patterns for length check
+        if (pattern.length > MAX_PATTERN_LENGTH) {
+            return null
         }
-        .let { pattern ->
-            when {
-                // If pattern ends with '/', it should match directories
-                pattern.endsWith("/") -> "$pattern.*"
-                // Otherwise match exactly or with a trailing slash for directories
-                else -> "$pattern(?:/.*)?$"
+        return pattern
+            // Escape special regex characters except * and ?
+            .replace(".", "\\.")
+            .replace("+", "\\+")
+            .replace("(", "\\(")
+            .replace(")", "\\)")
+            .replace("[", "\\[")
+            .replace("]", "\\]")
+            .replace("{", "\\{")
+            .replace("}", "\\}")
+            .replace(",", "\\,")
+            .replace("^", "\\^")
+            .replace("$", "\\$")
+            .replace("|", "\\|")
+            // Convert gitignore glob patterns to regex
+            .replace("**", ".*?") // Match any directory depth
+            .replace("*", "[^/]*?") // Match any character except path separator
+            .replace("?", "[^/]") // Match single character except path separator
+            .let { pattern ->
+                when {
+                    // If pattern starts with '/', anchor it to the start of the path
+                    pattern.startsWith("/") -> "^${pattern.substring(1)}"
+                    // If pattern doesn't start with '/', it can match anywhere in the path
+                    else -> "(?:^|.*/?)$pattern"
+                }
             }
-        }
+            .let { pattern ->
+                when {
+                    // If pattern ends with '/', it should match directories
+                    pattern.endsWith("/") -> "$pattern.*"
+                    // Otherwise match exactly or with a trailing slash for directories
+                    else -> "$pattern(?:/.*)?$"
+                }
+            }
+    }
 
     var selectedSourceFolder: VirtualFile
         set(newRoot) {
             _selectedSourceFolder = newRoot
         }
         get() = _selectedSourceFolder
+
+    companion object {
+        private const val MAX_PATTERN_LENGTH = 256 // Maximum allowed pattern length
+        private const val REGEX_TIMEOUT_MS = 100L  // Timeout for regex operations in milliseconds
+    }
 }
 
 data class ZipCreationResult(val payload: File, val checksum: String, val contentLength: Long)