VSCode Move Extension

Provides language support for the Move programming language. For information about Move visit the language documentation. It also provides early-stage support for trace-debugging Move unit tests using a familiar VSCode debugging interface (e.g., stepping through the code, tracking local variable names, setting line breakpoints).

How to Install

1. Open a new window in any Visual Studio Code application version 1.61.0 or greater.
2. Open the command palette (⇧ + ⌘ + P on macOS, or use the menu item View > Command Palette...) and type Extensions: Install Extensions. This will open a panel named Extensions in the sidebar of your Visual Studio Code window.
3. In the search bar labeled Search Extensions in Marketplace, type IOTA Foundation. The Move extension should appear as one of the option in the list below the search bar. Click Install.
4. Open any file that ends in .move.

Installation of the extension will also install a platform-specific pre-built move-analyzer binary in the default directory (see here for information on the location of this directory), overwriting the existing binary if it already exists. The move-analyzer binary is responsible for the advanced features of this VSCode extension (e.g., go to definition, type on hover). Please see Troubleshooting Section for situations when the pre-built move-analyzer binary is not available for your platform or if you want to use move-analyzer binary stored in a different location.

If you want to build, test, and trace Move code using the extension, you must install the iota binary on your machine - see here for instructions. The extension assumes that the iota binary is in your system path, but you can set its custom location location using VSCode's settings (⌘ + , on macOS, or use the menu item Code > Preferences > Settings). Search for the move.iota.path user setting, set it to the new location of the iota binary, and restart VSCode.

In order to trace-debug Move code execution, the iota binary must be built with the tracing feature flag. If your version of the iota binary was not built with this feature flag, an attempt to trace test execution will fail. In this case you may have to build the iota binary from source following these instructions.

Troubleshooting

What if the pre-built move-analyzer binary is not available for my platform?

If you are on Windows, the following answer assumes that your Windows user name is USER.

The move-analyzer language server is a Rust program which you can install manually provided that you have Rust development already installed. This can be done in two steps:

1. Install the move-analyzer installation prerequisites for your platform. They are the same as prerequisites for IOTA installation - for Linux, macOS and Windows these prerequisites and their installation instructions can be found here
2. Invoke cargo install --git https://github.com/iotaledger/iota iota-move-lsp to install the move-analyzer language server in your Cargo binary directory, which is typically located in the ~/.cargo/bin (macOS/Linux) or C:\Users\USER\.cargo\bin (Windows) directory.
3. Copy the move-analyzer binary to ~/.iota/bin (macOS/Linux) or C:\Users\USER\.iota\bin (Windows), which is its default location (create this directory if it does not exist).

What if I want to use a move-analyzer binary in a different location?

If you are on Windows, the following answer assumes that your Windows user name is USER.

If your move-analyzer binary is in a different directory than the default one (~/.iota/bin on macOS or Linux, or C:\Users\USER\.iota\bin on Windows), you may have the extension look for the binary at this new location using VSCode's settings (⌘ + , on macOS, or use the menu item Code > Preferences > Settings). Search for the iota-move.server.path user setting, set it to the new location of the move-analyzer binary, and restart VSCode.

What if advanced features (e.g., go to def) do not work, particularly after re-install or upgrade

Assuming you did not specify a different location for the move-analyzer binary and that the move-analyzer binary already exists in the default location (~/.iota/bin on macOS or Linux, or C:\Users\USER\.iota\bin on Windows), delete the existing move-analyzer binary and reinstall the extension.

What if everything else fails?

Check the IOTA Discord to see if the problem has already been reported and, if not, report it there.

Features

Here are some of the features of the Move Visual Studio Code extension. To see them, open a Move source file (a file with a .move file extension) and:

• See Move keywords and types highlighted in appropriate colors.
• Comment and un-comment lines of code (⌘ + / on macOS or the menu item Edit > Toggle Line Comment).
• Place your cursor on a delimiter, such as <, (, or {, and its corresponding delimiter -- >, ), or } -- will be highlighted.
• As you type, the editor will offer completion suggestions, in particular:
  • struct field name and method name suggestions following . being typed
  • suggestions following :: being typed
  • code snippets to complete init function and object type definitions
• If the opened Move source file is located within a buildable project (a Move.toml file can be found in one of its parent directories), the following advanced features will also be available:
  • compiler diagnostics
  • go to definition
  • go to type definition
  • go to references
  • type on hover
  • outline view showing symbol tree for Move source files
  • inlay hints:
    • types: local declarations, lambda parameters, variant and struct pattern matching
    • parameter names at function calls
• If the opened Move source file is located within a buildable project, and you have the iota binary installed, you can build and (locally) test this project using Move: Build a Move package and Move: Test a Move package commands from VSCode's command palette.
• If the opened Move source file is located within a buildable project, and you have the iota binary installed, you can trace-debug execution of Move unit tests within this project. This functionality is provided by this (Move) extension automatically including the Move Trace Debugging extension. Go to the Move Trace Debugging extension link to find more detailed information about trace-debugging and the current level of support. Trace-debugging a Move unit test is a two-step process:
  • first, you need to generate traces for Move unit tests by using Move: Trace Move test execution command from VSCode's command palette (traces will be available in the traces directory in JSON format)
  • second, you need to execute Run->Start Debugging menu command with Move file containing the test you want to trace-debug opened (if the file contains multiple tests, you will be able to select a specific one from a drop-down menu)