progress

lib/cartridge/cartridge.test.ts

@@ -7,6 +7,9 @@ import { CartridgeEvent } from "./cartridge_event.ts";
  */
 Deno.test("hello world", () => {
   const cartridge = new Cartridge();
+  cartridge.on(CartridgeEvent.Load, (event) => {
+    event.data;
+  });
   cartridge.on(CartridgeEvent.FileStart, console.log);
   assertEquals(1, 1);
 });

lib/cartridge/cartridge.ts

@@ -1,4 +1,4 @@
-import { CartridgeEvent } from "./cartridge_event.ts";
+import { CartridgeEvent, CartridgeEventReturnType } from "./cartridge_event.ts";
 import type {
   CartridgeEventContext,
   CartridgeHandler,
@@ -14,35 +14,35 @@ export class Cartridge {
     private handlers: CartridgeHandlerMap = {},
   ) {}
 
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.FileStart,
     handler: CartridgeHandler<CartridgeEvent.FileStart>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.InlineComment,
     handler: CartridgeHandler<CartridgeEvent.InlineComment>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.MultilineComment,
     handler: CartridgeHandler<CartridgeEvent.MultilineComment>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.Load,
     handler: CartridgeHandler<CartridgeEvent.Load>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.StructOpen,
     handler: CartridgeHandler<CartridgeEvent.StructOpen>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.SetProperty,
     handler: CartridgeHandler<CartridgeEvent.StructClose>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent.FileEnd,
     handler: CartridgeHandler<CartridgeEvent.FileEnd>,
   ): void;
-  addEventListener(
+  public addEventListener(
     name: CartridgeEvent,
     // deno-lint-ignore no-explicit-any
     handler: any,
@@ -53,12 +53,24 @@ export class Cartridge {
   /**
    * `on` is an alias for `addEventListener`
    */
-  on = this.addEventListener.bind(this);
+  public on = this.addEventListener.bind(this);
 
-  removeEventListener(name: CartridgeEvent) {
+  public removeEventListener(name: CartridgeEvent) {
     delete this.handlers[name];
   }
 
+  public async dispatch<T extends CartridgeEvent>(
+    name: CartridgeEvent,
+    ctx: CartridgeEventContext<T>,
+  ): Promise<string | null | void> {
+    const handleEvent = this.handlers[name] as CartridgeHandler<T>;
+    if (handleEvent === undefined) return null;
+    const executionResult = handleEvent(ctx);
+    return executionResult instanceof Promise
+      ? await executionResult
+      : executionResult;
+  }
+
   // TODO(@ethanthatonekid): add a `dispatch` method
   // @see <https://github.com/EthanThatOneKid/fart/blob/c43f233345/lib/gen/cart.ts#L120>
 }

lib/cartridge/cartridge_event.ts

@@ -11,9 +11,19 @@ export enum CartridgeEvent {
   FileEnd = "file_end",
 }
 
+export type CartridgeEventReturnType = (
+  | void
+  | Promise<void>
+  | string
+  | Promise<string>
+  | null
+);
+
 export interface CartridgeEventContext<T extends CartridgeEvent> {
   type: T;
-  code: { append: (code: string) => void };
+  code: {
+    append: (code: string) => CartridgeEventReturnType;
+  };
   tokens: Token[];
   data: T extends CartridgeEvent.InlineComment ? { comments: string[] }
     : T extends CartridgeEvent.MultilineComment ? { comments: string[] }
@@ -32,7 +42,7 @@ export interface CartridgeEventContext<T extends CartridgeEvent> {
  */
 export type CartridgeHandler<T extends CartridgeEvent> = (
   event: CartridgeEventContext<T>,
-) => void | Promise<void>;
+) => CartridgeEventReturnType;
 
 export interface CartridgeHandlerMap {
   [CartridgeEvent.FileStart]?: CartridgeHandler<CartridgeEvent.FileStart>;

lib/text_builder/code_block/code_block.test.ts → lib/code_block/code_block.test.ts

@@ -1,54 +1,54 @@
-import { assertEquals } from "../../../deps/std/testing.ts";
-import { CodeBlock } from "./code_block.ts";
-
-Deno.test("new code block is empty", () => {
-  assertEquals(new CodeBlock().export(), "");
-});
-
-Deno.test("add 3 lines of code to the block", () => {
-  const block = new CodeBlock();
-  block.append("a");
-  block.append("b");
-  block.append("c");
-  const expectation = "a\nb\nc";
-  const reality = block.export();
-  assertEquals(expectation, reality);
-});
-
-Deno.test("add 3 lines of code to the block (indented)", () => {
-  const block = new CodeBlock();
-  block.append("a", 0);
-  block.append("b", 1);
-  block.append("c", 2);
-  const expectation = "a\n  b\n    c";
-  const reality = block.export();
-  assertEquals(expectation, reality);
-});
-
-Deno.test("join 3 code blocks", () => {
-  const block1 = new CodeBlock();
-  block1.append("a", 0);
-  block1.append("b", 1);
-  block1.append("c", 2);
-  const block2 = new CodeBlock();
-  block2.append("d", 1);
-  block2.append("e", 0);
-  block2.append("f", 1);
-  const block3 = new CodeBlock();
-  block3.append("g", 2);
-  block3.append("h", 1);
-  block3.append("i", 0);
-  const expectation = `a
-  b
-    c
-
-  d
-e
-  f
-
-    g
-  h
-i`;
-  const reality = CodeBlock.join(block1, block2, block3);
-  assertEquals(expectation, reality);
-});
+import { assertEquals } from "../../deps/std/testing.ts";
+import { CodeBlock } from "./code_block.ts";
+
+Deno.test("new code block is empty", () => {
+  assertEquals(new CodeBlock().export(), "");
+});
+
+Deno.test("add 3 lines of code to the block", () => {
+  const block = new CodeBlock();
+  block.append("a");
+  block.append("b");
+  block.append("c");
+  const expectation = "a\nb\nc";
+  const reality = block.export();
+  assertEquals(expectation, reality);
+});
+
+Deno.test("add 3 lines of code to the block (indented)", () => {
+  const block = new CodeBlock();
+  block.append("a", 0);
+  block.append("b", 1);
+  block.append("c", 2);
+  const expectation = "a\n  b\n    c";
+  const reality = block.export();
+  assertEquals(expectation, reality);
+});
+
+Deno.test("join 3 code blocks", () => {
+  const block1 = new CodeBlock();
+  block1.append("a", 0);
+  block1.append("b", 1);
+  block1.append("c", 2);
+  const block2 = new CodeBlock();
+  block2.append("d", 1);
+  block2.append("e", 0);
+  block2.append("f", 1);
+  const block3 = new CodeBlock();
+  block3.append("g", 2);
+  block3.append("h", 1);
+  block3.append("i", 0);
+  const expectation = `a
+  b
+    c
+
+  d
+e
+  f
+
+    g
+  h
+i`;
+  const reality = CodeBlock.join(block1, block2, block3);
+  assertEquals(expectation, reality);
+});

lib/text_builder/code_block/code_block.ts → lib/code_block/code_block.ts

@@ -1,54 +1,58 @@
-import { getIndent, Indent, IndentOption } from "../../indent/mod.ts";
-
-export interface LineOfCode {
-  content: string;
-  indentLevel: number;
-}
-
-/**
- * Represents a block of code.
- */
-export class CodeBlock {
-  public code: LineOfCode[] = [];
-
-  append(content: string, indentLevel = 0): void {
-    this.code.push(
-      ...content.split("\n").map((line) => ({ content: line, indentLevel })),
-    );
-  }
-
-  export(indent: IndentOption = Indent.Space2): string {
-    return this.code
-      .map(({ content, indentLevel }) =>
-        getIndent(indent, indentLevel) + content
-      )
-      .join("\n");
-  }
-
-  /**
-   * `toString` is an alias for `CodeBlock.export`.
-   */
-  toString = this.export.bind(this);
-
-  static join(
-    indentOrFirstBlock: IndentOption | CodeBlock,
-    ...blocks: CodeBlock[]
-  ): string {
-    const blockPadding = 2; // lines between each code block
-    const blockSeparator = "\n".repeat(blockPadding);
-    const indentSpecified = !(indentOrFirstBlock instanceof CodeBlock);
-    if (!indentSpecified) blocks = [indentOrFirstBlock, ...blocks];
-    return blocks
-      .filter((block) => block !== null)
-      .reduce(
-        (file, block, i) => {
-          const exportedCode = indentSpecified
-            ? block.export(indentOrFirstBlock)
-            : block.export();
-          return file + exportedCode +
-            (blocks.length - 1 > i ? blockSeparator : "");
-        },
-        "",
-      );
-  }
-}
+import { getIndent, Indent, IndentOption } from "../indent/mod.ts";
+
+export interface LineOfCode {
+  content: string;
+  indentLevel: number;
+}
+
+/**
+ * Represents a block of code.
+ */
+export class CodeBlock {
+  public code: LineOfCode[] = [];
+
+  /**
+   * @param content string that is split up by line break
+   * @param indentLevel depth of nesting; defaults to 0
+   */
+  append(content: string, indentLevel = 0): void {
+    this.code.push(
+      ...content.split("\n").map((line) => ({ content: line, indentLevel })),
+    );
+  }
+
+  export(indent: IndentOption = Indent.Space2): string {
+    return this.code
+      .map(({ content, indentLevel }) =>
+        getIndent(indent, indentLevel) + content
+      )
+      .join("\n");
+  }
+
+  /**
+   * `toString` is an alias for `CodeBlock.export`.
+   */
+  toString = this.export.bind(this);
+
+  static join(
+    indentOrFirstBlock: IndentOption | CodeBlock,
+    ...blocks: CodeBlock[]
+  ): string {
+    const blockPadding = 2; // lines between each code block
+    const blockSeparator = "\n".repeat(blockPadding);
+    const indentSpecified = !(indentOrFirstBlock instanceof CodeBlock);
+    if (!indentSpecified) blocks = [indentOrFirstBlock, ...blocks];
+    return blocks
+      .filter((block) => block !== null)
+      .reduce(
+        (file, block, i) => {
+          const exportedCode = indentSpecified
+            ? block.export(indentOrFirstBlock)
+            : block.export();
+          const isLast = blocks.length - 1 <= i;
+          return file + exportedCode + (isLast ? "" : blockSeparator);
+        },
+        "",
+      );
+  }
+}

lib/text_builder/mod.ts

@@ -1,2 +1 @@
 export { TextBuilder } from "./text_builder.ts";
-export { CodeBlock } from "./code_block/mod.ts";

lib/text_builder/text_builder.ts

@@ -1,7 +1,8 @@
-import { CodeBlock } from "./code_block/mod.ts";
+import { CodeBlock } from "../code_block/mod.ts";
 import { Indent, IndentOption } from "../indent/mod.ts";
 import { Cartridge, CartridgeEvent } from "../cartridge/mod.ts";
 import { Token } from "../tokenize/mod.ts";
+import { makeFileStartEventContext } from "./utils.ts";
 
 export class TextBuilder {
   private blocks: CodeBlock[];
@@ -18,10 +19,14 @@ export class TextBuilder {
    * @todo @ethanthatonekid complete this method
    * @see https://github.com/EthanThatOneKid/fart/blob/c43f233345/lib/gen/builder.ts#L20
    */
-  // deno-lint-ignore no-unused-vars
-  append(event: CartridgeEvent, tokens: Token[]): void {
+  async append(event: CartridgeEvent, tokens: Token[]): Promise<void> {
     switch (event) {
       case CartridgeEvent.FileStart: {
+        const code = await this.cartridge.dispatch(
+          CartridgeEvent.FileStart,
+          makeFileStartEventContext(this.currentBlock, tokens),
+        );
+        if (typeof code === "string") this.currentBlock.append(code);
         break;
       }
       case CartridgeEvent.InlineComment: {

lib/text_builder/utils.ts

@@ -0,0 +1,8 @@
+import type { CodeBlock } from "../code_block/mod.ts";
+import type { Token } from "../tokenize/mod.ts";
+import { CartridgeEvent } from "../cartridge/mod.ts";
+
+export const makeFileStartEventContext = (
+  code: CodeBlock,
+  tokens: Token[],
+) => ({ type: CartridgeEvent.FileStart, code, tokens, data: null });