feat: auto-generate config schema from type

.github/workflows/ci.yml

@@ -43,12 +43,15 @@ jobs:
       - name: Generate documentation
         run: |
           bun run scripts/gen-docs-actions.ts --force && \
-          bun run scripts/gen-docs-api.ts --force
+          bun run scripts/gen-docs-api.ts --force && \
+          bun run scripts/gen-config-schema.ts
 
       - uses: actions/upload-artifact@v4
         with:
           name: dist
-          path: dist/
+          path: |
+            dist/
+            config.schema.json
           retention-days: 7
 
       - uses: actions/upload-artifact@v4

.gitignore

@@ -179,3 +179,5 @@ dist
 
 docs/command-reference
 docs/api-reference
+
+config.schema.json

scripts/gen-config-schema.ts

@@ -0,0 +1,118 @@
+import { log } from 'console'
+import { setProperty } from 'dot-prop'
+import { readFile, writeFile } from 'fs/promises'
+import { createSourceFile, ScriptTarget, SyntaxKind, type ArrayTypeNode, type Identifier, type PropertySignature, type TypeAliasDeclaration, type TypeLiteralNode } from 'typescript'
+
+function generateSchemaArray(node: ArrayTypeNode) {
+    const base = {
+        type: 'array',
+        items: {
+            type: '',
+        },
+    }
+
+    switch (node.elementType.kind) {
+        case SyntaxKind.StringKeyword:
+            base.items.type = 'string'
+            break
+        case SyntaxKind.NumberKeyword:
+            base.items.type = 'number'
+            break
+        case SyntaxKind.ObjectKeyword:
+            // FIXME: Implement
+            throw new Error('Arrays of objects are not supported yet!')
+        default:
+            base.items.type = 'null'
+            break
+    }
+
+    return base
+}
+
+function generateSchemaObject(node: TypeLiteralNode) {
+    const properties: Record<string, any> = {}
+
+    for (const member of node.members) {
+        const name = member.name as Identifier
+        properties[name.escapedText.toString()] = generateSchema(member as PropertySignature)
+    }
+
+    return {
+        type: 'object',
+        properties,
+    }
+}
+
+function generateSchema(node: PropertySignature) {
+    switch (node.type?.kind) {
+        case SyntaxKind.ArrayType:
+            return generateSchemaArray(node.type as ArrayTypeNode)
+        case SyntaxKind.TypeLiteral:
+            return generateSchemaObject(node.type as TypeLiteralNode)
+        case SyntaxKind.BooleanKeyword:
+            return {
+                type: 'boolean',
+            }
+        case SyntaxKind.StringKeyword:
+            return {
+                type: 'string',
+            }
+        default:
+            return {}
+    }
+}
+
+const file = 'cli/types.ts'
+const contents = await readFile(file)
+const ast = createSourceFile(file, contents.toString('utf8'), ScriptTarget.ESNext)
+
+const properties: Record<string, any> = {}
+
+for (const element of ast.statements) {
+    if (element.kind != SyntaxKind.TypeAliasDeclaration) {
+        continue
+    }
+
+    const declaration = element as TypeAliasDeclaration
+    if (declaration.name.escapedText === 'Config') {
+        const type = declaration.type as TypeLiteralNode
+        for (const member of type.members) {
+            const signature = member as PropertySignature
+            const name = signature.name as Identifier
+
+            properties[name.escapedText.toString()] = generateSchema(signature)
+        }
+        break
+    }
+}
+
+const { defaults } = await import('../cli/config.js')
+function generateDefaults(object: Record<string, any>, parent?: string) {
+    for (const key of Object.keys(object)) {
+        //@ts-ignore
+        const value = object[key]
+        const type = typeof value
+        const path = [parent, key].filter(k => k !== undefined).join('.')
+
+        if (type === 'object' && !Array.isArray(value)) {
+            generateDefaults(value, `${path}.properties`)
+            continue
+        }
+
+        if (value !== undefined) {
+            setProperty(properties, `${path}.default`, value)
+        }
+    }
+}
+generateDefaults(defaults)
+
+const schema = {
+    '$schema': 'http://json-schema.org/draft-07/schema#',
+    'type': 'object',
+    properties,
+}
+
+const schemaFile = 'config.schema.json'
+await writeFile(schemaFile, JSON.stringify(schema, null, 2) + '\n')
+
+log(`Wrote schema to ${schemaFile}`)