Template for creating a new SDK generator (#4010)

* Simple Unit Test Generator

* Generator Code

* Generator LANGUAGE_NAME

* Swift Init

* Writer and Astnode as commons

* More function functionality

* Lang Gen v2

* Lang Gen v3

* Oops

* Polish

* Writer indentation

* Polished imports

* Refined imports

* Template generator notes

* Template Generator

generators/commons/src/AstNode.ts

@@ -0,0 +1,25 @@
+import { Writer } from "./Writer";
+
+export abstract class AstNode {
+
+    private indentSize: number;
+
+    constructor(indentSize: number) {
+        this.indentSize = indentSize;
+    }
+
+    /**
+     * Every AST node knows how to write itself to a string.
+     */
+    public abstract write(writer: Writer): void;
+
+    /**
+     * Writes the node to a string.
+     */
+    public toString(): string {
+        const writer = new Writer(this.indentSize);
+        this.write(writer);
+        return writer.toString();
+    }
+
+}

generators/commons/src/Writer.ts

@@ -0,0 +1,64 @@
+import { AstNode } from "./AstNode";
+
+export declare namespace Writer {
+    interface Args {
+        tabSize?: number;
+    }
+}
+
+export class Writer {
+
+    private buffer: string;
+    private indentLevel: number;
+    private hasWrittenAnything: boolean;
+    private indentSize: number;
+
+    constructor(indentSize: number) {
+        this.buffer = "";
+        this.indentLevel = 0;
+        this.hasWrittenAnything = false;
+        this.indentSize = indentSize;
+    }
+
+    public write(text: string): void {
+
+        if (this.hasWrittenAnything) {
+            this.buffer += "\n";
+        }
+
+        const indent = this.getIndentString(this.indentSize);
+        const indentedText = indent + text.replace(/\n/g, `\n${indent}`);
+
+        this.buffer += indentedText;
+
+        this.hasWrittenAnything = true;
+
+    }
+
+    public newLine(): void {
+        this.buffer += "\n";
+    }
+
+    public openIndent(): void {
+        this.indentLevel++;
+    }
+
+    public closeIndent(): void {
+        if (this.indentLevel > 0) {
+            this.indentLevel--;
+        }
+    }
+
+    public writeNode(node: AstNode): void {
+        node.write(this);
+    }
+
+    public toString(): string {
+        return this.buffer;
+    }
+
+    private getIndentString(tabSize: number): string {
+        return " ".repeat(this.indentLevel * tabSize);
+    }
+
+}

generators/commons/src/index.ts

@@ -1,7 +1,9 @@
+export * from "./AbstractGeneratorCli";
+export * from "./AbstractGeneratorContext";
+export * from "./AstNode";
 export * from "./BaseGeneratorConfig";
 export * from "./ConfigUtilities";
-export * from "./AbstractGeneratorContext";
-export * from "./PersistedProject";
 export * from "./GeneratorNotificationService";
 export * from "./parseGeneratorConfig";
-export * from "./AbstractGeneratorCli";
+export * from "./PersistedProject";
+export * from "./Writer";

generators/commons/tsconfig.json

@@ -1,11 +1,25 @@
 {
   "extends": "../../shared/tsconfig.shared.json",
-  "compilerOptions": { "composite": true, "outDir": "lib", "rootDir": "src" },
-  "include": ["./src/**/*"],
+  "compilerOptions": {
+    "composite": true,
+    "outDir": "lib",
+    "rootDir": "src"
+  },
+  "include": [
+    "./src/**/*"
+  ],
   "references": [
-    { "path": "../../packages/cli/logger" },
-    { "path": "../../packages/commons/core-utils" },
-    { "path": "../../packages/commons/fs-utils" },
-    { "path": "../../packages/commons/logging-execa" }
+    {
+      "path": "../../packages/cli/logger"
+    },
+    {
+      "path": "../../packages/commons/core-utils"
+    },
+    {
+      "path": "../../packages/commons/fs-utils"
+    },
+    {
+      "path": "../../packages/commons/logging-execa"
+    }
   ]
-}
+}

generators/template/codegen/.prettierrc.cjs

@@ -0,0 +1 @@
+module.exports = require("fern/.prettierrc");

generators/template/codegen/jest.config.ts

@@ -0,0 +1 @@
+export { default } from "../../../shared/jest.config.shared";

generators/template/codegen/package.json

@@ -0,0 +1,48 @@
+{
+  "name": "@fern-api/LANGUAGE_NAME-codegen",
+  "version": "0.0.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/fern-api/fern.git",
+    "directory": "generators/LANGUAGE_NAME/codegen"
+  },
+  "files": [
+    "lib"
+  ],
+  "type": "module",
+  "source": "src/index.ts",
+  "main": "lib/index.js",
+  "types": "lib/index.d.ts",
+  "sideEffects": false,
+  "scripts": {
+    "clean": "rm -rf ./lib && tsc --build --clean",
+    "compile": "tsc --build",
+    "test": "yarn compile && jest --passWithNoTests",
+    "lint:eslint": "eslint --max-warnings 0 . --ignore-path=../../../.eslintignore",
+    "lint:eslint:fix": "yarn lint:eslint --fix",
+    "format": "prettier --write --ignore-unknown --ignore-path ../../../shared/.prettierignore \"**\"",
+    "format:check": "prettier --check --ignore-unknown --ignore-path ../../../shared/.prettierignore \"**\"",
+    "organize-imports": "organize-imports-cli tsconfig.json",
+    "depcheck": "depcheck"
+  },
+  "dependencies": {
+    "@fern-api/core-utils": "workspace:*",
+    "@fern-api/fs-utils": "workspace:*",
+    "@fern-api/generator-commons": "workspace:*",
+    "@fern-api/logging-execa": "workspace:*",
+    "@fern-fern/ir-sdk": "^32",
+    "lodash-es": "^4.17.21",
+    "ts-node": "^10.9.2",
+    "zod": "^3.22.3"
+  },
+  "devDependencies": {
+    "@types/jest": "^29.0.3",
+    "@types/lodash-es": "^4.17.12",
+    "@types/node": "^18.7.18",
+    "depcheck": "^1.4.6",
+    "eslint": "^8.56.0",
+    "jest": "^29.7.0",
+    "organize-imports-cli": "^0.10.0",
+    "typescript": "4.6.4"
+  }
+}

generators/template/codegen/src/ast/Class.ts

@@ -0,0 +1,44 @@
+import { AstNode, Writer } from "@fern-api/generator-commons";
+import Lang, { Func } from "../lang";
+
+export declare namespace Class {
+    interface Args {
+        name: string,
+        functions: Func[]
+    }
+}
+
+export class Class extends AstNode {
+
+    public readonly name: string;
+    public readonly functions: Func[];
+
+    constructor({ 
+        name,
+        functions,
+    }: Class.Args) {
+        super(Lang.indentSize);
+        this.name = name;
+        this.functions = functions;
+    }
+
+    public write(writer: Writer): void {
+
+        writer.write(`class ${this.name} {`);
+
+        writer.newLine();
+
+            writer.openIndent();
+
+            this.functions.forEach(func => {
+                writer.writeNode(func);
+                writer.newLine();
+            });
+
+            writer.closeIndent();
+
+        writer.write("}");
+
+
+    }
+}