Replaced the previous enum-based redirection logic with a cleaner, more modular Redirection trait. By abstracting redirection types (stdout, stderr, and their append variants) into dedicated structs, the codebase is significantly more maintainable and easier to extend with new redirection behaviors. This refactor simplifies command execution handling across the shell's internals.

This update moves from procedural command parsing and execution to an object-oriented approach using traits and structs. Key changes include defining a Command trait for builtins and external commands, introducing a Shell struct to encapsulate state and logic, and updating tests to reflect this architecture. This transition makes the code more maintainable and cleaner to extend with future shell features.

We've added a new 'reflect' skill to the project, designed to proactively capture user feedback and synthesize recurring workflow patterns into durable memory rules. By codifying lessons learned from previous corrections and interaction styles, the system can now adapt its behavior to better align with user preferences over time. This update effectively turns every session's corrections into actionable internal documentation.

Added a new suite of integration tests for core shell built-in commands including pwd, type, and cd. These tests cover functional requirements, redirection handling, and error states, ensuring shell stability across common operations. This significantly improves our test coverage for command execution and filesystem navigation.

Improved the developer experience by updating executable tab completion to support longest common prefix matching. When multiple matches exist, the first tab press now completes to the common prefix, while the second tab press lists all available suggestions. This adjustment ensures more intuitive navigation when working with similar command names.

This change adds custom Tab key handling on top of the existing rustyline completer to track consecutive Tab presses and surface multiple matches more like a real shell. Single matches still complete directly, while ambiguous input now beeps on the first Tab and prints the available built-in commands and executable names from PATH on the second. The result is a much more usable interactive experience when discovering or disambiguating commands.

This update cleans up the project’s internal skill docs by moving AI collaboration and workflow reflection material into the dedicated reflect skill and trimming rust-shell-dev back to functional implementation guidance. The Rust shell skill now focuses on concrete development actions, while shared behavioral learnings like confirmation before destructive actions and correction handling live in one canonical place. The practical effect is less duplicated guidance and clearer boundaries between execution instructions and accumulated workflow memory.

This change extends the Rust shell development skill guide with an "AI Collaboration & Workflow" section that captures lessons from recent interactions, including how to modify code with better context, communicate intentions more proactively, and interpret user feedback more accurately. Although it’s a documentation-only update, it strengthens the team’s working conventions around AI-assisted development and should help future edits be more aligned and transparent. The practical effect is smoother collaboration and fewer mismatches during iterative development.

This commit updates the Rust shell development skill documentation with a reflection on technical achievements, bug fixes, and workflow best practices learned while building interactive shell features. The change is documentation-only, but it helps preserve hard-won implementation knowledge for future contributors working on similar shell behavior and debugging issues. The practical effect is better project memory and onboarding, not a runtime change.

This change extends shell completion beyond built-in commands by parsing PATH directories and searching them for matching executables during tab completion. The completion flow in main.rs now merges built-in command suggestions with discovered binaries, and tests.rs adds coverage to verify executable completion works as expected while also cleaning up a couple of syntax/test annotation issues from earlier refactors. In practice, the shell should now feel much more like a real interactive environment when completing commands.

This commit introduces a new reflect skill that captures user corrections as reusable rules and can also infer repeatable workflows into new skill definitions. It also updates the existing rust-shell-dev skill to explicitly check those learned corrections first, so future shell work can incorporate prior feedback instead of repeating the same mistakes. The net effect is a more adaptive development workflow with lightweight memory built into the repo.

This commit introduces a new agent skill under .github/skills for the CodeCrafters Rust shell, documenting how to add builtin commands, where to update execution logic and completion metadata, and what constraints to follow when fixing argument parsing. It also codifies a validation checklist around cargo test and completion-specific tests so changes are less likely to regress existing behavior. The practical effect is a clearer, more repeatable workflow for future shell-related contributions.

This change fixes command completion UX by making successful tab-completed command suggestions return command instead of command. The implementation updates MyHelper::get_suggestions in src/main.rs and aligns the test suite in src/tests.rs with the new output, which also resolves the reported remote test failure. In practice, command entry now behaves more like a standard shell and feels a bit smoother.

This change swaps the plain stdin loop for a rustyline-based editor, giving the shell a more usable interactive experience with line editing, persistent history behavior, and tab completion for built-ins like echo, exit, type, pwd, and cd. It also introduces completion tests and fixes command parsing so quoted filenames in redirections are unquoted correctly, addressing a real usability bug alongside the UX upgrade. The practical effect is a shell that feels much closer to a real terminal and behaves more reliably during everyday use.

This change extends command parsing and execution to recognize append-style stdout and stderr redirection, covering both builtins and external commands. The command runner was refactored into a reusable execute_command function, and file handling now switches between truncate and append modes based on the redirect operator. A substantial set of tests was added for parsing, builtin behavior, external command behavior, and realistic shell scenarios, which makes the new redirection semantics much safer to evolve. Practically, the shell can now accumulate output in files the way developers expect.

This changes parse_args from a simple single-quote split into a character-by-character parser that tracks both single- and double-quoted sections. As a result, inputs like echo "hello world" now stay grouped as one argument, and adjacent quoted segments are concatenated consistently, which also updates the previous behavior for cases like 'hello''world'. The accompanying tests lock in the new quoting behavior, making command parsing more predictable for real shell-style input.

This commit cleans up redirection handling in src/main.rs by separating built-in command output into distinct stdout and stderr buffers, then routing each one according to the parsed redirect target. Errors from commands like cd, pwd, and unknown commands no longer bypass redirection logic, and the shell now handles > vs 2> more consistently for both built-ins and external commands. The practical effect is that redirected output behaves much more like a real shell, especially in failure cases.