Go step definitions support (#130)

* Add support for go

- Support for Godog 'Given', 'When', 'Then' and 'Step' step definition keywords
- Support for 'interpreted_string_literal' and 'raw_string_literal' expressions
- Godog snippet implementation

---------

Co-authored-by: Aslak Hellesøy <1000+aslakhellesoy@users.noreply.github.com>
Co-authored-by: Kieran Ryan <kierankilkenny@gmail.com>

CHANGELOG.md

@@ -10,10 +10,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - (Python) Fix index failures from partial parameter type matches ([#196](https://github.com/cucumber/language-service/pull/196))
 - (Rust) Support for r# raw strings with step definition patterns ([#176](https://github.com/cucumber/language-service/pull/176))
 - (Rust) Line continuation characters in rust step definition patterns ([#179](https://github.com/cucumber/language-service/pull/179))
-- (Python) Unexpected spaces and commas in generated step definitions [#160](https://github.com/cucumber/language-service/issues/160)
+- (Python) Unexpected spaces and commas in generated step definitions ([#160](https://github.com/cucumber/language-service/issues/160))
 
 ### Added
 - (Python) Support for u-strings with step definition patterns ([#173](https://github.com/cucumber/language-service/pull/173))
+- (Go) Support for Godog step definitions ([#130](https://github.com/cucumber/language-service/pull/130))
 
 ## [1.4.1] - 2023-07-16
 ### Fixed

README.md

@@ -4,7 +4,7 @@
   Cucumber Language Service
 </h1>
 <p align="center">
-  <b>Cucumber language services used by <a href="https://github.com/cucumber/language-server#readme">Cucumber Language Server</a> and <a href="https://github.com/cucumber/monaco#readme">Cucumber Monaco</a>.</b>
+  <b>Cucumber language services used by <a href="https://github.com/cucumber/language-server#readme">Cucumber Language Server</a> and <a href="https://github.com/cucumber/monaco#readme">Cucumber Monaco</a></b>
 </p>
 
 <p align="center">
@@ -36,7 +36,7 @@
 - 🌎 Gherkin localisation
 - 📖 Language support
   - C#
-  - [Go](https://github.com/cucumber/language-service/issues/72)
+  - Go
   - Java
   - JavaScript
   - PHP

package.json

@@ -75,6 +75,7 @@
     "tree-sitter": "0.20.6",
     "tree-sitter-c-sharp": "0.20.0",
     "tree-sitter-cli": "0.20.8",
+    "tree-sitter-go": "0.20.0",
     "tree-sitter-java": "0.20.2",
     "tree-sitter-php": "0.20.0",
     "tree-sitter-python": "0.20.4",

scripts/build.js

@@ -40,6 +40,11 @@ const languages = [
     dir: '',
     wasm: 'rust',
   },
+  {
+    npm: 'tree-sitter-go',
+    dir: '',
+    wasm: 'go',
+  },
 ]
 
 // Build wasm parsers for supported languages

src/language/goLanguage.ts

@@ -0,0 +1,68 @@
+import { StringOrRegExp } from '@cucumber/cucumber-expressions'
+
+import { unsupportedOperation } from './helpers.js'
+import { Language, TreeSitterSyntaxNode } from './types.js'
+
+export const goLanguage: Language = {
+  toParameterTypeName: unsupportedOperation,
+  toParameterTypeRegExps: unsupportedOperation,
+  toStepDefinitionExpression(node: TreeSitterSyntaxNode): StringOrRegExp {
+    const text = stringLiteral(node)
+    const hasRegExpAnchors = text[0] == '^' || text[text.length - 1] == '$'
+    return hasRegExpAnchors ? new RegExp(text) : text
+  },
+  // Empty array as Godog does not support Cucumber Expressions
+  defineParameterTypeQueries: [],
+  defineStepDefinitionQueries: [
+    `(function_declaration
+      body: (block
+        (expression_statement
+          (call_expression
+            function: (selector_expression
+              field: (field_identifier) @annotation-name
+            )
+            arguments: (argument_list
+              [
+                (raw_string_literal) @expression
+              ]
+            )
+            (#match? @annotation-name "Given|When|Then|Step")))))@root
+    `,
+    `(function_declaration
+      body: (block
+        (expression_statement
+          (call_expression
+            function: (selector_expression
+              field: (field_identifier) @annotation-name
+            )
+            arguments: (argument_list
+              [
+                (interpreted_string_literal) @expression
+              ]
+            )
+            (#match? @annotation-name "Given|When|Then|Step")))))@root
+    `,
+  ],
+  snippetParameters: {
+    int: { type: 'int', name: 'i' },
+    float: { type: 'float', name: 'f' },
+    word: { type: 'string' },
+    string: { type: 'string', name: 's' },
+    double: { type: 'float', name: 'd' },
+    bigdecimal: { type: 'float64', name: 'bigDecimal' },
+    byte: { type: 'rune', name: 'b' },
+    short: { type: 'int32', name: 's' },
+    long: { type: 'int64', name: 'l' },
+    biginteger: { type: 'int64', name: 'bigInteger' },
+    '': { type: 'string', name: 'arg' },
+  },
+  defaultSnippetTemplate: `
+  // Generated with Cucumber Expressions syntax, which are not supported by Godog. Convert to Regular Expressions.
+  ctx.{{ keyword }}(\`{{ expression }}\`, <stepFunc>)
+`,
+}
+
+export function stringLiteral(node: TreeSitterSyntaxNode | null): string {
+  if (node === null) throw new Error('node cannot be null')
+  return node.text.slice(1, -1)
+}

src/language/helpers.ts

@@ -70,3 +70,7 @@ export function filter(
 function flatten(node: TreeSitterSyntaxNode): TreeSitterSyntaxNode[] {
   return node.children.reduce((r, o) => [...r, ...flatten(o)], [node])
 }
+
+export function unsupportedOperation(): never {
+  throw new Error('Unsupported operation')
+}

src/language/languages.ts

@@ -1,4 +1,5 @@
 import { csharpLanguage } from './csharpLanguage.js'
+import { goLanguage } from './goLanguage.js'
 import { javaLanguage } from './javaLanguage.js'
 import { javascriptLanguage } from './javascriptLanguage.js'
 import { phpLanguage } from './phpLanguage.js'
@@ -17,6 +18,7 @@ const languageByName: Record<LanguageName, Language> = {
   rust: rustLanguage,
   python: pythonLanguage,
   javascript: javascriptLanguage,
+  go: goLanguage,
 }
 
 export function getLanguage(languageName: LanguageName): Language {

src/language/phpLanguage.ts

@@ -1,12 +1,9 @@
+import { unsupportedOperation } from './helpers.js'
 import { Language } from './types.js'
 
 export const phpLanguage: Language = {
-  toParameterTypeName() {
-    throw new Error('Unsupported operation')
-  },
-  toParameterTypeRegExps() {
-    throw new Error('Unsupported operation')
-  },
+  toParameterTypeName: unsupportedOperation,
+  toParameterTypeRegExps: unsupportedOperation,
   toStepDefinitionExpression(node) {
     // match multiline comment
     const text = node.text

src/language/types.ts

@@ -44,6 +44,7 @@ export const LanguageNames = [
   'ruby',
   'rust',
   'javascript',
+  'go',
 ] as const
 export type LanguageName = (typeof LanguageNames)[number]
 

src/service/getGenerateSnippetCodeAction.ts

@@ -22,7 +22,7 @@ import { stepDefinitionSnippet } from './snippet/stepDefinitionSnippet.js'
  * @param link where the snippet should be added
  * @param relativePath the relative path from the workspace root
  * @param createFile true if link.targetUri does not exist
- * @param mustacheTemplate template to generae the snippet
+ * @param mustacheTemplate template to generate the snippet
  * @param languageName the name of the language we're generating for
  * @param registry parameter types
  */

src/tree-sitter-node/NodeParserAdapter.ts

@@ -3,6 +3,8 @@ import Parser, { Query } from 'tree-sitter'
 // @ts-ignore
 import Csharp from 'tree-sitter-c-sharp'
 // @ts-ignore
+import Go from 'tree-sitter-go'
+// @ts-ignore
 import Java from 'tree-sitter-java'
 // @ts-ignore
 import Php from 'tree-sitter-php'
@@ -48,6 +50,9 @@ export class NodeParserAdapter implements ParserAdapter {
       case 'rust':
         this.parser.setLanguage(Rust)
         break
+      case 'go':
+        this.parser.setLanguage(Go)
+        break
       default:
         throw new Error(`Unsupported language: ${languageName}`)
     }

test/language/goLanguage.test.ts

@@ -0,0 +1,22 @@
+import assert from 'assert'
+
+import { stringLiteral } from '../../src/language/goLanguage.js'
+import { TreeSitterSyntaxNode } from '../../src/language/types.js'
+
+describe('goLanguage', () => {
+  it('should remove enclosing string quotations and backticks', () => {
+    const cases = ['`^I eat (d+)$`', '"^I eat (d+)$"']
+
+    cases.forEach((expression) => {
+      const node: TreeSitterSyntaxNode = {
+        type: 'raw_string_literal',
+        text: expression,
+        startPosition: { row: 1, column: 19 },
+        endPosition: { row: 1, column: 19 + expression.length },
+        children: [],
+      }
+      const result = stringLiteral(node)
+      assert.deepStrictEqual(result, '^I eat (d+)$')
+    })
+  })
+})

test/language/testdata/go/StepDefinitions.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"github.com/cucumber/godog"
+)
+
+func a_regexp() {}
+
+func InitializeScenario(ctx *godog.ScenarioContext) {
+	ctx.Given(`^a regexp$`, a_regexp)
+}