wtf is ergen?

ergen is a small command line tool for Go programmers that automatically writes the repetitive error checking code Go requires after almost every function call. In Go, whenever a function might fail, the standard pattern is to write a block that checks if an error happened and handles it, and typing this out by hand for every call gets tedious. ergen reads your source file, figures out where your cursor is, and generates a correctly shaped error check block for you in a fraction of a second. What makes it more than a simple text snippet is that it actually reads the surrounding code using Go's own parsing tools. It looks at what the enclosing function returns, and builds a matching block that fills in the right placeholder values for anything that is not an error, such as zero, an empty string, or an empty version of a custom type. It even looks across other files in the same folder to understand custom types your project has defined, so the generated code matches what your project actually expects rather than guessing. The README reports it runs in well under ten milliseconds from start to finish, which is fast enough to trigger as a keyboard shortcut while typing. You install it with a single Go command, then wire it up as a task or keybinding in your editor, with instructions given for Zed, VS Code, and Neovim. You can also drop a configuration file into your project to customize what kind of error block gets generated in different situations, for example writing to a test failure in test files versus returning an HTTP error in a web handler. The project does not use any AI models. It relies entirely on static analysis of your Go code's structure, which the README presents as a speed and reliability advantage over language server suggestions or simpler community tools that do not resolve custom types.