VS Code snippets for files with specific extension

Question

Visual Studio Code allows creating snippets, separated for various language syntaxes. But is it possible to specify not only language, but also extension of a particular file for created snippet?

For example: I want to create snippet specifically for c# .csproj file. This file has xml syntax, and I could create snippet as an xml snippet, but I don't want to see this snippet in other xml files except .csproj.

Answer 1

For snippets you use the scope parameter:

"FrontMatter": {
  "scope": "csharp",         // put your language identifier here
  "prefix": "frontmatter",
  "body": [
      "...",
  ]
},

If that scope isn't specific enough, use a keybinding instead which allows for more specificity.

scope cannot take content like editorTextFocus && !editorReadonly && resourceExtname =~ /\\.csproj/.

----------- for keybindings you can use the below -----------

"when": "editorTextFocus && !editorReadonly && resourceExtname =~ /\\.csproj/ && editorLangId == csharp"

See when clause operator

The =~ operator allows the use of regular expressions on the right-hand side, so you could do somethinh like

resourceExtname =~ /\\.(html|css|scss) to restrict to those three extensions. It seems odd to me that you do have to specifically add the . prior to the extension itself, but it seems you do.

A keybinding which refers to a snippet by name - the snippet itself is defined in one of your snippet files follows:

{
  "key": "alt+l",
  "command": "editor.action.insertSnippet",
  "args": {
    "name": "My groovy comment style"
  },
  "when": "editorTextFocus && !editorReadonly && resourceExtname =~ /\\.csproj/ && editorLangId == csharp"
},

or with the actual snippet body right in the keybinding:

{
  "key": "alt+m",
  "command": "editor.action.insertSnippet",
  "when": "editorTextFocus && !editorReadonly && resourceExtname =~ /\\.csproj/ && editorLangId == csharp",
  "args": {
      "snippet": "${TM_SELECTED_TEXT/([a-z])([A-Z]+(?=[A-Z]))|([A-Z][a-z])/$1 ${2:/downcase}${3:/downcase}/g}"
  }
},