feat(languages): rescript (#1616)

* Add rescript language support

* cargo xtask docgen

* Add textobjects & file line ending

* Fix text objects & rerun docgen

* Fix textobjects queries

7 files changed, 212 insertions, 0 deletions

diff --git a/.gitmodules b/.gitmodules
index d35b0f33..55ed97b3 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -222,3 +222,7 @@
 	path = helix-syntax/languages/tree-sitter-twig
 	url = https://github.com/eirabben/tree-sitter-twig.git
 	shallow = true
+[submodule "helix-syntax/languages/tree-sitter-rescript"]
+	path = helix-syntax/languages/tree-sitter-rescript
+	url = https://github.com/jaredramirez/tree-sitter-rescript
+	shallow = true
diff --git a/book/src/generated/lang-support.md b/book/src/generated/lang-support.md
index d10b56f1..64dab6d3 100644
--- a/book/src/generated/lang-support.md
+++ b/book/src/generated/lang-support.md
@@ -46,6 +46,7 @@
 | python | ✓ | ✓ | ✓ | `pylsp` |
 | racket |  |  |  | `racket` |
 | regex | ✓ |  |  |  |
+| rescript | ✓ | ✓ |  | `rescript-language-server` |
 | ruby | ✓ |  | ✓ | `solargraph` |
 | rust | ✓ | ✓ | ✓ | `rust-analyzer` |
 | scala | ✓ |  | ✓ | `metals` |
diff --git a/helix-syntax/languages/tree-sitter-rescript b/helix-syntax/languages/tree-sitter-rescript
new file mode 160000
+Subproject 761eb9126b65e078b1b5770ac296b4af8870f93
diff --git a/languages.toml b/languages.toml
index 74c01da5..041d1564 100644
--- a/languages.toml
+++ b/languages.toml
@@ -602,3 +602,14 @@ scope = "source.iex"
 injection-regex = "iex"
 file-types = ["iex"]
 roots = []
+
+[[language]]
+name = "rescript"
+scope = "source.rescript"
+injection-regex = "rescript"
+file-types = ["res"]
+roots = ["bsconfig.json"]
+auto-format = true
+comment-token = "//"
+language-server = { command = "rescript-language-server", args = ["--stdio"] }
+indent = { tab-width = 2, unit = "  " }
diff --git a/runtime/queries/rescript/highlights.scm b/runtime/queries/rescript/highlights.scm
new file mode 100644
index 00000000..b9ab8ea6
--- /dev/null
+++ b/runtime/queries/rescript/highlights.scm
@@ -0,0 +1,179 @@
+(comment) @comment
+
+; Identifiers
+;------------
+
+; Escaped identifiers like \"+."
+((value_identifier) @function.macro
+ (#match? @function.macro "^\\.*$"))
+
+[
+  (type_identifier)
+  (unit_type)
+  "list"
+] @type
+
+[
+  (variant_identifier)
+  (polyvar_identifier)
+] @constant
+
+(property_identifier) @variable.other.member
+(module_identifier) @namespace
+
+(jsx_identifier) @tag
+(jsx_attribute (property_identifier) @variable.parameter)
+
+; Parameters
+;----------------
+
+(list_pattern (value_identifier) @variable.parameter)
+(spread_pattern (value_identifier) @variable.parameter)
+
+; String literals
+;----------------
+
+[
+  (string)
+  (template_string)
+] @string
+
+(template_substitution
+  "${" @punctuation.bracket
+  "}" @punctuation.bracket) @embedded
+
+(character) @constant.character
+(escape_sequence) @constant.character.escape
+
+; Other literals
+;---------------
+
+[
+  (true)
+  (false)
+] @constant.builtin
+
+(number) @constant.numeric
+(polyvar) @constant
+(polyvar_string) @constant
+
+; Functions
+;----------
+
+[
+ (formal_parameters (value_identifier))
+ (positional_parameter (value_identifier))
+ (labeled_parameter (value_identifier))
+] @variable.parameter
+
+(function parameter: (value_identifier) @variable.parameter)
+
+; Meta
+;-----
+
+[
+ "@"
+ "@@"
+ (decorator_identifier)
+] @label
+
+(extension_identifier) @keyword
+("%") @keyword
+
+; Misc
+;-----
+
+(subscript_expression index: (string) @variable.other.member)
+(polyvar_type_pattern "#" @constant)
+
+[
+  ("include")
+  ("open")
+] @keyword
+
+[
+  "as"
+  "export"
+  "external"
+  "let"
+  "module"
+  "mutable"
+  "private"
+  "rec"
+  "type"
+  "and"
+] @keyword
+
+[
+  "if"
+  "else"
+  "switch"
+] @keyword
+
+[
+  "exception"
+  "try"
+  "catch"
+  "raise"
+] @keyword
+
+[
+  "."
+  ","
+  "|"
+] @punctuation.delimiter
+
+[
+  "++"
+  "+"
+  "+."
+  "-"
+  "-."
+  "*"
+  "*."
+  "/"
+  "/."
+  "<"
+  "<="
+  "=="
+  "==="
+  "!"
+  "!="
+  "!=="
+  ">"
+  ">="
+  "&&"
+  "||"
+  "="
+  ":="
+  "->"
+  "|>"
+  ":>"
+  (uncurry)
+] @operator
+
+[
+  "("
+  ")"
+  "{"
+  "}"
+  "["
+  "]"
+] @punctuation.bracket
+
+(polyvar_type
+  [
+   "["
+   "[>"
+   "[<"
+   "]"
+  ] @punctuation.bracket)
+
+[
+  "~"
+  "?"
+  "=>"
+  "..."
+] @punctuation
+
+(ternary_expression ["?" ":"] @operator)
diff --git a/runtime/queries/rescript/injections.scm b/runtime/queries/rescript/injections.scm
new file mode 100644
index 00000000..201cce75
--- /dev/null
+++ b/runtime/queries/rescript/injections.scm
@@ -0,0 +1,8 @@
+((comment) @injection.content
+ (#set! injection.language "comment"))
+
+((raw_js) @injection.content
+ (#set! injection.language "javascript"))
+
+((raw_gql) @injection.content
+ (#set! injection.language "graphql"))
diff --git a/runtime/queries/rescript/textobjects.scm b/runtime/queries/rescript/textobjects.scm
new file mode 100644
index 00000000..7ee8cd1a
--- /dev/null
+++ b/runtime/queries/rescript/textobjects.scm
@@ -0,0 +1,9 @@
+; Classes (modules)
+;------------------
+
+(module_declaration definition: ((_) @class.inside)) @class.around
+
+; Functions
+;----------
+
+(function body: (_) @function.inside) @function.around