Add scala support (#237)

Author: yzia2000

CHANGELOG.md

@@ -7,8 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
-### Fixed
+### Added
+- Add Scala support ([#237](https://github.com/cucumber/language-service/issues/237))
 
+### Fixed
 - Missing `parameter:cucumber` token for Scenario Outline ([#246](https://github.com/cucumber/language-service/issues/246))
 
 ## [1.7.0] - 2025-05-18

README.md

@@ -43,6 +43,7 @@
   - Python
   - Ruby
   - Rust
+  - Scala
   - TypeScript
   - TypeScript JSX (TSX)
 - 🗂 Document symbols (Display document outline tree)

scripts/build.js

@@ -45,6 +45,11 @@ const languages = [
     dir: '',
     wasm: 'go',
   },
+  {
+    npm: 'tree-sitter-scala',
+    dir: '',
+    wasm: 'scala',
+  },
 ]
 
 // Build wasm parsers for supported languages
@@ -69,11 +74,19 @@ if (!fs.existsSync(treeSitterCli)) {
     let command
     if (process.env.CI) {
       console.log(`Compiling ${module}`)
-      command = `node_modules/.bin/tree-sitter build ${module} --wasm`
+      if (module.endsWith('tree-sitter-php')) {
+        command = `node_modules/.bin/tree-sitter build --wasm ${module}/php`
+      } else {
+        command = `node_modules/.bin/tree-sitter build --wasm ${module}`
+      }
     } else {
       console.log(`Compiling ${module} inside docker`)
       // https://github.com/tree-sitter/tree-sitter/issues/1560
-      command = `node_modules/.bin/tree-sitter build ${module} --wasm --docker`
+      if (module.endsWith('tree-sitter-php')) {
+        command = `node_modules/.bin/tree-sitter build --wasm ${module}/php --docker`
+      } else {
+        command = `node_modules/.bin/tree-sitter build --wasm ${module} --docker`
+      }
     }
     exec(command, (err) => {
       if (err) {

src/language/languages.ts

@@ -6,6 +6,7 @@ import { phpLanguage } from './phpLanguage.js'
 import { pythonLanguage } from './pythonLanguage.js'
 import { rubyLanguage } from './rubyLanguage.js'
 import { rustLanguage } from './rustLanguage.js'
+import { scalaLanguage } from './scalaLanguage.js'
 import { tsxLanguage } from './tsxLanguage.js'
 import { Language, LanguageName } from './types.js'
 
@@ -19,6 +20,7 @@ const languageByName: Record<LanguageName, Language> = {
   python: pythonLanguage,
   javascript: javascriptLanguage,
   go: goLanguage,
+  scala: scalaLanguage,
 }
 
 export function getLanguage(languageName: LanguageName): Language {

src/language/scalaLanguage.ts

@@ -0,0 +1,86 @@
+import { Language, TreeSitterSyntaxNode } from './types.js'
+
+export const scalaLanguage: Language = {
+  toParameterTypeName(node) {
+    switch (node.type) {
+      case 'string': {
+        return stringLiteral(node)
+      }
+      case 'identifier': {
+        return node.text
+      }
+      default: {
+        throw new Error(`Unsupported node type ${node.type}`)
+      }
+    }
+  },
+  toParameterTypeRegExps(node) {
+    if (node === null) {
+      return /.*/
+    }
+    return stringLiteral(node)
+  },
+  toStepDefinitionExpression(node) {
+    if (node.type === 'string') {
+      const text = stringLiteral(node)
+      const hasRegExpAnchors = text[0] == '^' || text[text.length - 1] == '$'
+      return hasRegExpAnchors ? new RegExp(text) : text
+    }
+    throw new Error(`Unsupported node type ${node.type}`)
+  },
+
+  defineParameterTypeQueries: [
+    `
+(call_expression
+  function: (identifier) @function-name
+  arguments: (arguments
+   [
+      (string)+ @name
+   ]
+  )
+  (#match? @function-name "ParameterType")
+) @root
+`,
+  ],
+  defineStepDefinitionQueries: [
+    `
+(call_expression
+  function: (identifier) @function-name
+  arguments: (arguments
+    (
+      (string) @expression
+    )
+  )
+  (#match? @function-name "Given|When|Then|And|But")
+) @root
+`,
+  ],
+  snippetParameters: {
+    int: { type: 'Int', name: 'i' },
+    float: { type: 'Float', name: 'f' },
+    word: { type: 'String' },
+    string: { type: 'String', name: 's' },
+    double: { type: 'Double', name: 'd' },
+    bigdecimal: { type: 'scala.math.BigDecimal', name: 'bigDecimal' },
+    byte: { type: 'Byte', name: 'b' },
+    short: { type: 'Short', name: 's' },
+    long: { type: 'Long', name: 'l' },
+    biginteger: { type: 'scala.math.BigInteger', name: 'bigInteger' },
+    '': { type: 'Any', name: 'arg' },
+  },
+  defaultSnippetTemplate: `
+{{ keyword }}("""{{ expression }}""") { ({{ #parameters }}{{ #seenParameter }}, {{ /seenParameter }}{{ name }}: {{ type }}{{ /parameters }}) =>
+  // {{ blurb }}
+}
+`,
+}
+
+export function stringLiteral(node: TreeSitterSyntaxNode | null): string {
+  if (node === null) throw new Error('node cannot be null')
+  if (node.text.startsWith('"""')) {
+    const x = node.text.slice(3, -3)
+    console.log(x)
+    return x
+  }
+  return node.text.slice(1, -1)
+}

src/language/types.ts

@@ -45,6 +45,7 @@ export const LanguageNames = [
   'rust',
   'javascript',
   'go',
+  'scala',
 ] as const
 export type LanguageName = (typeof LanguageNames)[number]
 

src/tree-sitter-node/NodeParserAdapter.ts

@@ -15,6 +15,8 @@ import Ruby from 'tree-sitter-ruby'
 // @ts-ignore
 import Rust from 'tree-sitter-rust'
 // @ts-ignore
+import Scala from 'tree-sitter-scala'
+// @ts-ignore
 import TypeScript from 'tree-sitter-typescript'
 
 import { LanguageName, ParserAdapter } from '../language/types.js'
@@ -53,6 +55,9 @@ export class NodeParserAdapter implements ParserAdapter {
       case 'go':
         this.parser.setLanguage(Go)
         break
+      case 'scala':
+        this.parser.setLanguage(Scala)
+        break
       default:
         throw new Error(`Unsupported language: ${languageName}`)
     }

test/language/ExpressionBuilder.test.ts

@@ -18,6 +18,7 @@ const cucumberExpressionsSupport: Set<LanguageName> = new Set([
   'ruby',
   'rust',
   'tsx',
+  'scala',
 ])
 
 function defineContract(makeParserAdapter: () => ParserAdapter) {

test/language/testdata/scala/ParameterTypes.scala

@@ -0,0 +1,14 @@
+class ParameterTypes extends ScalaDsl with EN {
+
+    ParameterType("uuid", "[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}") { uuid: String =>
+        uuid
+    }
+
+    ParameterType("date", "\\d{4}-\\d{2}-\\d{2}") { date: String =>
+        LocalDate.parse(date)
+    }
+
+    ParameterType("planet", "(jupiter|mars|tellus)") { planet: String =>
+        planet
+    }
+}

test/language/testdata/scala/StepDefinitions.scala

@@ -0,0 +1,23 @@
+import io.cucumber.scala.{EN, ScalaDsl, Scenario}
+import org.junit.Assert._
+
+class StepDefinitions extends ScalaDsl with EN {
+
+  Given("a {uuid}") { (uuid: String) =>
+  }
+
+  When("a {date}") { (date: Date) =>
+  }
+
+  Then("a {planet}") { (date: Date) =>
+  }
+
+  Then("""^a regexp$""") { (x: Date) =>
+  }
+
+  But("an {undefined-parameter}") { (date: Date) =>
+  }
+
+  Given("the bee's knees") { (date: Date) =>
+  }
+}