Go HTML Language Server

Full language support for Go html/template and text/template files in VS Code.

Features

Completions

• Dot completions — type . to see fields and methods of the bound Go struct
• Nested chains — .User. lists fields/methods of the User struct
• Scope-aware — inside {{range .Items}}, . completes with the element type's fields
• Template names — {{template " suggests all defined templates
• Keywords — {{ triggers keyword completions (if, range, with, define, block, etc.)
• Built-in functions — len, index, printf, eq, etc. with signatures and docs
• Custom FuncMap functions — functions registered via .Funcs() in your Go code
• Snippets — 40+ snippets for common patterns (if/end, range/end, with/end, etc.)
• HTML completions — tags, attributes, and values outside {{ }} actions

Hover

• Fields — shows type name and doc comment
• Nested chains — .User.Name shows the deepest field's type
• Functions — shows signature and documentation (builtins + custom FuncMap)
• Variables — $v shows the variable name and resolved type
• Template references — {{template "x"}} shows the definition location
• Range variables — $i resolves to int, $v resolves to element type
• Method chains — .GetUser.Name follows return types
• HTML elements — shows MDN documentation for HTML tags and attributes

Go to Definition

• Template references — {{template "x"}} jumps to {{define "x"}}
• Struct fields — {{.Field}} jumps to the Go struct field declaration
• Nested chains — {{.User.Name}} jumps to the Name field on the User struct
• Methods — jumps to the method declaration in Go source
• Scope-aware — works correctly inside {{range}} and {{with}} blocks

Diagnostics

• Syntax errors — real-time parse error reporting
• Undefined templates — {{template "x"}} where x has no {{define "x"}}
• Undefined fields — {{.Foo}} where Foo doesn't exist on the bound struct
• Chain validation — {{.User.Phone}} reports Phone undefined on User
• Scope-aware — validates fields inside {{range}} and {{with}} against the correct type

Find References

• All {{template "x"}} call sites and the {{define "x"}} location

Rename

• F2 on template names renames across all files ({{define}}, {{template}}, {{block}})

Code Actions

• Typo quick fixes — "Did you mean .Title?" for misspelled field/method names

Formatting

• Normalizes whitespace inside {{ }} actions
• Preserves trim markers ({{- and -}})
• Does not touch HTML content outside actions

Syntax Highlighting

• Full TextMate grammar for Go templates in HTML
• Semantic token highlighting for keywords, variables, properties, functions, strings, comments, and operators
• Injection grammar for Go template syntax in .html files

Supported File Extensions

How It Works

The extension bundles a zero-dependency LSP server written in Go. It analyzes your Go source files to understand:

• Which structs are passed to template.Execute() / template.ExecuteTemplate()
• Which files are parsed via template.ParseFiles() / template.ParseGlob()
• Which custom functions are registered via .Funcs(template.FuncMap{...})

This gives you type-aware completions, hover, diagnostics, and go-to-definition that understands your actual Go types — not just the template syntax.

HTML language features (completions, hover) are provided client-side via vscode-html-languageservice for content outside template actions.

Configuration

Requirements

• Go project with html/template or text/template usage
• Go source files in the workspace root (the LSP scans .go files for template bindings)

License

MIT