add declaration generator

Author: omermecitoglu

src/core/renderers/declaration.ts

@@ -0,0 +1,17 @@
+import type { OpenAPI } from "~/core/openapi";
+import { type DeclaredOperation, resolveDeclaredOperations } from "~/core/resolvers/declared-operation";
+import getTemplate from "~/core/template";
+import declarationTemplate from "~/templates/declaration.hbs";
+
+type DeclarationTemplate = {
+  importedSchemas: string[],
+  operations: DeclaredOperation[],
+};
+
+export default function generateDeclaration(importedSchemas: string[], paths: OpenAPI["paths"]) {
+  const template = getTemplate<DeclarationTemplate>(declarationTemplate);
+  return template({
+    importedSchemas,
+    operations: resolveDeclaredOperations(paths),
+  });
+}

src/core/resolvers/declared-operation.ts

@@ -0,0 +1,26 @@
+import type { OpenAPI, Operation } from "~/core/openapi";
+import getContentSchema from "./content";
+import resolveEndpoints from "./enpoint";
+import { resolveOperationParams } from "./operation-param";
+import { resolveSchema } from "./schema-definition";
+
+export type DeclaredOperation = {
+  name: string,
+  parameters: string,
+  result: string,
+};
+
+function resolveOperationResult(responses: Operation["responses"]) {
+  const schemas = Object.values(responses).map(response => {
+    return response.content ? resolveSchema(getContentSchema(response.content)) : null;
+  });
+  return schemas.find(s => typeof s === "string") ?? "unknown";
+}
+
+export function resolveDeclaredOperations(paths: OpenAPI["paths"]) {
+  return resolveEndpoints(paths).map<DeclaredOperation>(({ operation }) => ({
+    name: operation.operationId,
+    parameters: resolveOperationParams(operation, true).join(", "),
+    result: resolveOperationResult(operation.responses),
+  }));
+}

src/index.ts

@@ -4,6 +4,7 @@ import path from "node:path";
 import getAppName from "./core/app";
 import getArgument from "./core/arguments";
 import createFile from "./core/file";
+import generateDeclaration from "./core/renderers/declaration";
 import generateInterface from "./core/renderers/interface";
 import generateSchema from "./core/renderers/schema";
 import { resolveSchemas, resolveSchemasFromProps } from "./core/resolvers/imported-schema";
@@ -37,4 +38,7 @@ import generateSwaggerJson from "./core/swagger";
 
   const content = generateInterface(envName, resolvedPaths);
   await createFile(content, "index.js", outputDir);
+
+  const declaration = generateDeclaration(schemas, data.paths);
+  await createFile(declaration, "index.d.ts", outputDir);
 })();

src/templates/declaration.hbs

@@ -0,0 +1,6 @@
+{{#each importedSchemas}}
+import type {{this}} from "./schemas/{{this}}";
+{{/each}}
+{{#each operations}}
+export declare function {{name}}({{parameters}}): Promise<{{result}}>;
+{{/each}}