add clippy warning for string_slice (#5422)

Co-authored-by: Douwe Osinga <douwe@squareup.com>

Cargo.toml

@@ -12,6 +12,7 @@ description = "An AI agent"
 
 [workspace.lints.clippy]
 uninlined_format_args = "allow"
+string_slice = "warn"
 
 [workspace.dependencies]
 rmcp = { version = "0.8.3", features = ["schemars", "auth"] }

crates/goose-cli/src/session/completion.rs

@@ -26,7 +26,7 @@ impl GooseCompleter {
     /// Complete prompt names for the /prompt command
     fn complete_prompt_names(&self, line: &str) -> Result<(usize, Vec<Pair>)> {
         // Get the prefix of the prompt name being typed
-        let prefix = if line.len() > 8 { &line[8..] } else { "" };
+        let prefix = line.get(8..).unwrap_or("");
 
         // Get available prompts from cache
         let cache = self.completion_cache.read().unwrap();
@@ -156,7 +156,7 @@ impl GooseCompleter {
 
     /// Complete argument keys for a specific prompt
     fn complete_argument_keys(&self, line: &str) -> Result<(usize, Vec<Pair>)> {
-        let parts: Vec<&str> = line[8..].split_whitespace().collect();
+        let parts: Vec<&str> = line.get(8..).unwrap_or("").split_whitespace().collect();
 
         // We need at least the prompt name
         if parts.is_empty() {

crates/goose-cli/src/session/input.rs

@@ -169,15 +169,17 @@ fn handle_slash_command(input: &str) -> Option<InputResult> {
             }
         }
         s if s.starts_with(CMD_EXTENSION) => Some(InputResult::AddExtension(
-            s[CMD_EXTENSION.len()..].to_string(),
+            s.get(CMD_EXTENSION.len()..).unwrap_or("").to_string(),
         )),
-        s if s.starts_with(CMD_BUILTIN) => {
-            Some(InputResult::AddBuiltin(s[CMD_BUILTIN.len()..].to_string()))
+        s if s.starts_with(CMD_BUILTIN) => Some(InputResult::AddBuiltin(
+            s.get(CMD_BUILTIN.len()..).unwrap_or("").to_string(),
+        )),
+        s if s.starts_with(CMD_MODE) => Some(InputResult::GooseMode(
+            s.get(CMD_MODE.len()..).unwrap_or("").to_string(),
+        )),
+        s if s.starts_with(CMD_PLAN) => {
+            parse_plan_command(s.get(CMD_PLAN.len()..).unwrap_or("").trim().to_string())
         }
-        s if s.starts_with(CMD_MODE) => {
-            Some(InputResult::GooseMode(s[CMD_MODE.len()..].to_string()))
-        }
-        s if s.starts_with(CMD_PLAN) => parse_plan_command(s[CMD_PLAN.len()..].trim().to_string()),
         s if s == CMD_ENDPLAN => Some(InputResult::EndPlan),
         s if s == CMD_CLEAR => Some(InputResult::Clear),
         s if s.starts_with(CMD_RECIPE) => parse_recipe_command(s),
@@ -199,7 +201,7 @@ fn parse_recipe_command(s: &str) -> Option<InputResult> {
     }
 
     // Extract the filepath from the command
-    let filepath = s[CMD_RECIPE.len()..].trim();
+    let filepath = s.get(CMD_RECIPE.len()..).unwrap_or("").trim();
 
     if filepath.is_empty() {
         return Some(InputResult::Recipe(None));

crates/goose-mcp/src/developer/analyze/formatter.rs

@@ -1,11 +1,11 @@
-use rmcp::model::{Content, Role};
-use std::collections::{HashMap, HashSet};
-use std::path::{Path, PathBuf};
-
 use crate::developer::analyze::types::{
     AnalysisMode, AnalysisResult, CallChain, EntryType, FocusedAnalysisData,
 };
 use crate::developer::lang;
+use goose::utils::safe_truncate;
+use rmcp::model::{Content, Role};
+use std::collections::{HashMap, HashSet};
+use std::path::{Path, PathBuf};
 
 pub struct Formatter;
 
@@ -164,13 +164,7 @@ impl Formatter {
                     if imports.len() > 1 {
                         format!("{}({})", group, imports.len())
                     } else {
-                        // For single imports, show more detail
-                        let imp = &imports[0];
-                        if imp.len() > 40 {
-                            format!("{}...", &imp[..37])
-                        } else {
-                            imp.clone()
-                        }
+                        safe_truncate(&imports[0], 40)
                     }
                 })
                 .collect();
@@ -727,7 +721,7 @@ impl Formatter {
                 if let Some(header_line) = output
                     .lines()
                     .rev()
-                    .find(|l| l.starts_with("##") && line.contains(&l[3..]))
+                    .find(|l| l.starts_with("##") && l.get(3..).is_some_and(|s| line.contains(s)))
                 {
                     if !filtered.contains(header_line) {
                         filtered.push_str(header_line);

crates/goose-mcp/src/developer/analyze/languages/go.rs

@@ -87,7 +87,7 @@ pub fn find_method_for_receiver(
             for i in 0..parent.child_count() {
                 if let Some(child) = parent.child(i) {
                     if child.kind() == "field_identifier" {
-                        return Some(source[child.byte_range()].to_string());
+                        return source.get(child.byte_range()).map(|s| s.to_string());
                     }
                 }
             }

crates/goose-mcp/src/developer/analyze/languages/ruby.rs

@@ -140,7 +140,7 @@ fn find_method_in_body_with_depth(
                 for j in 0..child.child_count() {
                     if let Some(name_node) = child.child(j) {
                         if name_node.kind() == "identifier" {
-                            return Some(source[name_node.byte_range()].to_string());
+                            return source.get(name_node.byte_range()).map(|s| s.to_string());
                         }
                     }
                 }

crates/goose-mcp/src/developer/analyze/languages/rust.rs

@@ -83,7 +83,9 @@ pub fn extract_function_name_for_kind(
         for i in 0..node.child_count() {
             if let Some(child) = node.child(i) {
                 if child.kind() == "type_identifier" {
-                    return Some(format!("impl {}", &source[child.byte_range()]));
+                    return source
+                        .get(child.byte_range())
+                        .map(|s| format!("impl {}", s));
                 }
             }
         }
@@ -109,7 +111,7 @@ pub fn find_method_for_receiver(
             for i in 0..parent.child_count() {
                 if let Some(child) = parent.child(i) {
                     if child.kind() == "identifier" {
-                        return Some(source[child.byte_range()].to_string());
+                        return source.get(child.byte_range()).map(|s| s.to_string());
                     }
                 }
             }
@@ -133,7 +135,7 @@ pub fn find_receiver_type(node: &tree_sitter::Node, source: &str) -> Option<Stri
             for i in 0..parent.child_count() {
                 if let Some(child) = parent.child(i) {
                     if child.kind() == "type_identifier" {
-                        return Some(source[child.byte_range()].to_string());
+                        return source.get(child.byte_range()).map(|s| s.to_string());
                     }
                 }
             }

crates/goose-mcp/src/developer/analyze/parser.rs

@@ -103,7 +103,8 @@ impl ElementExtractor {
         source: &str,
         kinds: &[&str],
     ) -> Option<String> {
-        Self::find_child_by_kind(node, kinds).map(|child| source[child.byte_range()].to_string())
+        Self::find_child_by_kind(node, kinds)
+            .and_then(|child| source.get(child.byte_range()).map(|s| s.to_string()))
     }
 
     pub fn extract_with_depth(
@@ -216,8 +217,13 @@ impl ElementExtractor {
         for match_ in matches.by_ref() {
             for capture in match_.captures {
                 let node = capture.node;
-                let text = &source[node.byte_range()];
-                let line = source[..node.start_byte()].lines().count() + 1;
+                let Some(text) = source.get(node.byte_range()) else {
+                    continue;
+                };
+                let line = source
+                    .get(..node.start_byte())
+                    .map(|s| s.lines().count() + 1)
+                    .unwrap_or(1);
 
                 match query.capture_names()[capture.index as usize] {
                     "func" | "const" => {
@@ -284,18 +290,25 @@ impl ElementExtractor {
         for match_ in matches.by_ref() {
             for capture in match_.captures {
                 let node = capture.node;
-                let text = &source[node.byte_range()];
+                let Some(text) = source.get(node.byte_range()) else {
+                    continue;
+                };
                 let start_pos = node.start_position();
 
-                let line_start = source[..node.start_byte()]
-                    .rfind('\n')
+                let line_start = source
+                    .get(..node.start_byte())
+                    .and_then(|s| s.rfind('\n'))
                     .map(|i| i + 1)
                     .unwrap_or(0);
-                let line_end = source[node.end_byte()..]
-                    .find('\n')
+                let line_end = source
+                    .get(node.end_byte()..)
+                    .and_then(|s| s.find('\n'))
                     .map(|i| node.end_byte() + i)
                     .unwrap_or(source.len());
-                let context = source[line_start..line_end].trim().to_string();
+                let context = source
+                    .get(line_start..line_end)
+                    .map(|s| s.trim().to_string())
+                    .unwrap_or_default();
 
                 let caller_name = Self::find_containing_function(&node, source, language);
 
@@ -356,18 +369,25 @@ impl ElementExtractor {
         for match_ in matches.by_ref() {
             for capture in match_.captures {
                 let node = capture.node;
-                let text = &source[node.byte_range()];
+                let Some(text) = source.get(node.byte_range()) else {
+                    continue;
+                };
                 let start_pos = node.start_position();
 
-                let line_start = source[..node.start_byte()]
-                    .rfind('\n')
+                let line_start = source
+                    .get(..node.start_byte())
+                    .and_then(|s| s.rfind('\n'))
                     .map(|i| i + 1)
                     .unwrap_or(0);
-                let line_end = source[node.end_byte()..]
-                    .find('\n')
+                let line_end = source
+                    .get(node.end_byte()..)
+                    .and_then(|s| s.find('\n'))
                     .map(|i| node.end_byte() + i)
                     .unwrap_or(source.len());
-                let context = source[line_start..line_end].trim().to_string();
+                let context = source
+                    .get(line_start..line_end)
+                    .map(|s| s.trim().to_string())
+                    .unwrap_or_default();
 
                 let capture_name = query.capture_names()[capture.index as usize];
 

crates/goose-mcp/src/developer/editor_models/morphllm_editor.rs

@@ -28,8 +28,9 @@ impl MorphLLMEditor {
         if let (Some(start_pos), Some(end_pos)) = (text.find(&start_tag), text.find(&end_tag)) {
             if start_pos < end_pos {
                 let content_start = start_pos + start_tag.len();
-                let content = &text[content_start..end_pos];
-                return Some(content.trim().to_string());
+                if let Some(content) = text.get(content_start..end_pos) {
+                    return Some(content.trim().to_string());
+                }
             }
         }
         None

crates/goose-mcp/src/developer/rmcp_developer.rs

@@ -1335,20 +1335,22 @@ impl DeveloperServer {
 
                 // Find the last space before AM/PM and replace it with U+202F
                 let space_pos = filename.rfind(meridian)
-                    .map(|pos| filename[..pos].trim_end().len())
+                    .and_then(|pos| filename.get(..pos).map(|s| s.trim_end().len()))
                     .unwrap_or(0);
 
                 if space_pos > 0 {
                     let parent = path.parent().unwrap_or(Path::new(""));
-                    let new_filename = format!(
-                        "{}{}{}",
-                        &filename[..space_pos],
-                        '\u{202F}',
-                        &filename[space_pos+1..]
-                    );
-                    let new_path = parent.join(new_filename);
+                    if let (Some(before), Some(after)) = (filename.get(..space_pos), filename.get(space_pos+1..)) {
+                        let new_filename = format!(
+                            "{}{}{}",
+                            before,
+                            '\u{202F}',
+                            after
+                        );
+                        let new_path = parent.join(new_filename);
 
-                    return new_path;
+                        return new_path;
+                    }
                 }
             }
         }
@@ -3208,7 +3210,10 @@ mod tests {
             ) {
                 let start_idx = start + start_tag.len();
                 if start_idx < end {
-                    let path = assistant_content.text[start_idx..end].trim();
+                    let Some(path) = assistant_content.text.get(start_idx..end).map(|s| s.trim())
+                    else {
+                        panic!("Failed to extract path from assistant content");
+                    };
                     println!("Extracted path: {}", path);
 
                     let file_contents =

crates/goose-test/src/mcp/stdio/playback.rs

@@ -20,7 +20,7 @@ struct LogEntry {
 fn parse_log_line(line: &str) -> Option<LogEntry> {
     line.find(": ").and_then(|pos| {
         let (prefix, content) = line.split_at(pos);
-        let content = &content[2..]; // Skip ": "
+        let content = content.get(2..)?; // Skip ": "
 
         let stream_type = match prefix {
             "STDIN" => StreamType::Stdin,

crates/goose/src/agents/agent.rs

@@ -1365,17 +1365,9 @@ impl Agent {
             .unwrap_or(&content)
             .trim()
             .to_string();
-        tracing::debug!(
-            "Cleaned content for parsing: {}",
-            &clean_content[..std::cmp::min(200, clean_content.len())]
-        );
 
-        // try to parse json response from the LLM
-        tracing::debug!("Attempting to parse recipe content as JSON");
         let (instructions, activities) =
             if let Ok(json_content) = serde_json::from_str::<Value>(&clean_content) {
-                tracing::debug!("Successfully parsed JSON content");
-
                 let instructions = json_content
                     .get("instructions")
                     .ok_or_else(|| anyhow!("Missing 'instructions' in json response"))?

crates/goose/src/agents/subagent_execution_tool/tasks.rs

@@ -249,7 +249,7 @@ fn extract_json_from_line(line: &str) -> Option<String> {
         return None;
     }
 
-    let potential_json = &line[start..=end];
+    let potential_json = line.get(start..=end)?;
     if serde_json::from_str::<Value>(potential_json).is_ok() {
         Some(potential_json.to_string())
     } else {

crates/goose/src/providers/claude_code.rs

@@ -9,7 +9,7 @@ use tokio::process::Command;
 
 use super::base::{ConfigKey, Provider, ProviderMetadata, ProviderUsage, Usage};
 use super::errors::ProviderError;
-use super::utils::RequestLog;
+use super::utils::{filter_extensions_from_system_prompt, RequestLog};
 use crate::config::{Config, GooseMode};
 use crate::conversation::message::{Message, MessageContent};
 use crate::model::ModelConfig;
@@ -103,28 +103,6 @@ impl ClaudeCodeProvider {
         None
     }
 
-    /// Filter out the Extensions section from the system prompt
-    fn filter_extensions_from_system_prompt(&self, system: &str) -> String {
-        // Find the Extensions section and remove it
-        if let Some(extensions_start) = system.find("# Extensions") {
-            // Look for the next major section that starts with #
-            let after_extensions = &system[extensions_start..];
-            if let Some(next_section_pos) = after_extensions[1..].find("\n# ") {
-                // Found next section, keep everything before Extensions and after the next section
-                let before_extensions = &system[..extensions_start];
-                let next_section_start = extensions_start + next_section_pos + 1;
-                let after_next_section = &system[next_section_start..];
-                format!("{}{}", before_extensions.trim_end(), after_next_section)
-            } else {
-                // No next section found, just remove everything from Extensions onward
-                system[..extensions_start].trim_end().to_string()
-            }
-        } else {
-            // No Extensions section found, return original
-            system.to_string()
-        }
-    }
-
     /// Convert goose messages to the format expected by claude CLI
     fn messages_to_claude_format(&self, _system: &str, messages: &[Message]) -> Result<Value> {
         let mut claude_messages = Vec::new();
@@ -303,8 +281,7 @@ impl ClaudeCodeProvider {
                 ProviderError::RequestFailed(format!("Failed to format messages: {}", e))
             })?;
 
-        // Create a filtered system prompt without Extensions section
-        let filtered_system = self.filter_extensions_from_system_prompt(system);
+        let filtered_system = filter_extensions_from_system_prompt(system);
 
         if std::env::var("GOOSE_CLAUDE_CODE_DEBUG").is_ok() {
             println!("=== CLAUDE CODE PROVIDER DEBUG ===");

crates/goose/src/providers/cursor_agent.rs

@@ -9,7 +9,7 @@ use tokio::process::Command;
 
 use super::base::{ConfigKey, Provider, ProviderMetadata, ProviderUsage, Usage};
 use super::errors::ProviderError;
-use super::utils::RequestLog;
+use super::utils::{filter_extensions_from_system_prompt, RequestLog};
 use crate::conversation::message::{Message, MessageContent};
 use crate::model::ModelConfig;
 use rmcp::model::Tool;
@@ -112,34 +112,11 @@ impl CursorAgentProvider {
         None
     }
 
-    /// Filter out the Extensions section from the system prompt
-    fn filter_extensions_from_system_prompt(&self, system: &str) -> String {
-        // Find the Extensions section and remove it
-        if let Some(extensions_start) = system.find("# Extensions") {
-            // Look for the next major section that starts with #
-            let after_extensions = &system[extensions_start..];
-            if let Some(next_section_pos) = after_extensions[1..].find("\n# ") {
-                // Found next section, keep everything before Extensions and after the next section
-                let before_extensions = &system[..extensions_start];
-                let next_section_start = extensions_start + next_section_pos + 1;
-                let after_next_section = &system[next_section_start..];
-                format!("{}{}", before_extensions.trim_end(), after_next_section)
-            } else {
-                // No next section found, just remove everything from Extensions onward
-                system[..extensions_start].trim_end().to_string()
-            }
-        } else {
-            // No Extensions section found, return original
-            system.to_string()
-        }
-    }
-
     /// Convert goose messages to a simple prompt format for cursor-agent CLI
     fn messages_to_cursor_agent_format(&self, system: &str, messages: &[Message]) -> String {
         let mut full_prompt = String::new();
 
-        // Add system prompt
-        let filtered_system = self.filter_extensions_from_system_prompt(system);
+        let filtered_system = filter_extensions_from_system_prompt(system);
         full_prompt.push_str(&filtered_system);
         full_prompt.push_str("\n\n");
 
@@ -267,7 +244,7 @@ impl CursorAgentProvider {
             println!("Original system prompt length: {} chars", system.len());
             println!(
                 "Filtered system prompt length: {} chars",
-                self.filter_extensions_from_system_prompt(system).len()
+                filter_extensions_from_system_prompt(system).len()
             );
             println!("Full prompt: {}", prompt);
             println!("Model: {}", self.model.model_name);

crates/goose/src/providers/formats/snowflake.rs

@@ -133,7 +133,9 @@ pub fn parse_streaming_response(sse_data: &str) -> Result<Message> {
             continue;
         }
 
-        let json_str = &line[6..]; // Remove "data: " prefix
+        let Some(json_str) = line.get(6..) else {
+            continue;
+        }; // Remove "data: " prefix
         if json_str.trim().is_empty() || json_str.trim() == "[DONE]" {
             continue;
         }

crates/goose/src/providers/gemini_cli.rs

@@ -8,7 +8,7 @@ use tokio::process::Command;
 
 use super::base::{Provider, ProviderMetadata, ProviderUsage, Usage};
 use super::errors::ProviderError;
-use super::utils::RequestLog;
+use super::utils::{filter_extensions_from_system_prompt, RequestLog};
 use crate::conversation::message::{Message, MessageContent};
 
 use crate::model::ModelConfig;
@@ -103,28 +103,6 @@ impl GeminiCliProvider {
         None
     }
 
-    /// Filter out the Extensions section from the system prompt
-    fn filter_extensions_from_system_prompt(&self, system: &str) -> String {
-        // Find the Extensions section and remove it
-        if let Some(extensions_start) = system.find("# Extensions") {
-            // Look for the next major section that starts with #
-            let after_extensions = &system[extensions_start..];
-            if let Some(next_section_pos) = after_extensions[1..].find("\n# ") {
-                // Found next section, keep everything before Extensions and after the next section
-                let before_extensions = &system[..extensions_start];
-                let next_section_start = extensions_start + next_section_pos + 1;
-                let after_next_section = &system[next_section_start..];
-                format!("{}{}", before_extensions.trim_end(), after_next_section)
-            } else {
-                // No next section found, just remove everything from Extensions onward
-                system[..extensions_start].trim_end().to_string()
-            }
-        } else {
-            // No Extensions section found, return original
-            system.to_string()
-        }
-    }
-
     /// Execute gemini CLI command with simple text prompt
     async fn execute_command(
         &self,
@@ -135,8 +113,7 @@ impl GeminiCliProvider {
         // Create a simple prompt combining system + conversation
         let mut full_prompt = String::new();
 
-        // Add system prompt
-        let filtered_system = self.filter_extensions_from_system_prompt(system);
+        let filtered_system = filter_extensions_from_system_prompt(system);
         full_prompt.push_str(&filtered_system);
         full_prompt.push_str("\n\n");
 

crates/goose/src/providers/githubcopilot.rs

@@ -169,7 +169,9 @@ impl GithubCopilotProvider {
                     if !tline.starts_with("data: ") {
                         continue;
                     }
-                    let payload = &tline[6..];
+                    let Some(payload) = tline.get(6..) else {
+                        continue;
+                    };
                     if payload == "[DONE]" {
                         break;
                     }

crates/goose/src/providers/sagemaker_tgi.rs

@@ -246,7 +246,7 @@ impl SageMakerTgiProvider {
         // Remove any remaining HTML-like tags using a simple pattern
         // This is a basic implementation - for production use, consider using a proper HTML parser
         while let Some(start) = result.find('<') {
-            if let Some(end) = result[start..].find('>') {
+            if let Some(end) = result.get(start..).and_then(|s| s.find('>')) {
                 result.replace_range(start..start + end + 1, "");
             } else {
                 break;

crates/goose/src/providers/utils.rs

@@ -47,6 +47,31 @@ pub fn convert_image(image: &ImageContent, image_format: &ImageFormat) -> Value
     }
 }
 
+pub fn filter_extensions_from_system_prompt(system: &str) -> String {
+    let Some(extensions_start) = system.find("# Extensions") else {
+        return system.to_string();
+    };
+
+    let Some(after_extensions) = system.get(extensions_start + 1..) else {
+        return system.to_string();
+    };
+
+    if let Some(next_section_pos) = after_extensions.find("\n# ") {
+        let Some(before) = system.get(..extensions_start) else {
+            return system.to_string();
+        };
+        let Some(after) = system.get(extensions_start + next_section_pos + 1..) else {
+            return system.to_string();
+        };
+        format!("{}{}", before.trim_end(), after)
+    } else {
+        system
+            .get(..extensions_start)
+            .map(|s| s.trim_end().to_string())
+            .unwrap_or_else(|| system.to_string())
+    }
+}
+
 fn check_context_length_exceeded(text: &str) -> bool {
     let check_phrases = [
         "too long",

crates/goose/src/providers/utils_universal_openai_stream.rs

@@ -275,7 +275,9 @@ data: [DONE]
             if !line.starts_with("data: ") {
                 continue;
             }
-            let payload = &line[6..];
+            let Some(payload) = line.get(6..) else {
+                continue;
+            };
             if payload == "[DONE]" {
                 break;
             }
@@ -325,7 +327,9 @@ data: [DONE]
             if !line.starts_with("data: ") {
                 continue;
             }
-            let payload = &line[6..];
+            let Some(payload) = line.get(6..) else {
+                continue;
+            };
             if payload == "[DONE]" {
                 break;
             }
@@ -377,7 +381,9 @@ data: [DONE]
             if !line.starts_with("data: ") {
                 continue;
             }
-            let payload = &line[6..];
+            let Some(payload) = line.get(6..) else {
+                continue;
+            };
             if payload == "[DONE]" {
                 break;
             }

scripts/test_providers.sh

@@ -51,7 +51,7 @@ for provider_config in "${PROVIDERS[@]}"; do
     echo "Model: ${MODEL}"
     echo ""
     TMPFILE=$(mktemp)
-    (cd "$TESTDIR" && "$SCRIPT_DIR/target/release/goose" run --text "please list files in the current directory" --with-builtin developer,autovisualiser,computercontroller,tutorial  2>&1) | tee "$TMPFILE"
+    (cd "$TESTDIR" && "$SCRIPT_DIR/target/release/goose" run --text "please list files in the current directory" --with-builtin developer,autovisualiser,computercontroller,tutorial,todo,extensionmanager  2>&1) | tee "$TMPFILE"
     echo ""
     if grep -q "shell | developer" "$TMPFILE"; then
       echo "✓ SUCCESS: Test passed - developer tool called"