#61, starting StringStringMap

use-cases/build/StringStringMap.ts

@@ -1,5 +1,45 @@
-export default function buildStringStringMap(): Promise<void>
+import path from "path";
+import {
+  distDir,
+  project,
+  removeDistFile,
+  //getExistingSourceFile,
+} from "./sharedProject.js";
+import { SourceFile } from "ts-morph";
+
+export default async function buildStringStringMap(): Promise<void>
 {
-  console.log("Hello World!");
+  await removeDistFile("StringStringMap.ts");
+
+  /* This is a starting point, based on our needs:
+  - hashing two keys into one
+  - retrieving two keys from one
+  - storing the hashed keys and values in a private map
+  */
+  const moduleFile: SourceFile = project.createSourceFile(
+    path.join(distDir, "StringStringMap.ts"),
+    `
+interface StringStringKey {
+  readonly firstKey: string,
+  readonly secondKey: string
+}
+
+export default class StringStringMap<V> {
+  static #hashKeys(firstKey: string, secondKey: string): string {
+    return JSON.stringify({firstKey, secondKey});
+  }
+
+  static #parseKeys(hashedKey: string): [string, string]
+  {
+    const { firstKey, secondKey } = JSON.parse(hashedKey) as StringStringKey;
+    return [firstKey, secondKey];
+  }
+
+  readonly #hashMap = new Map<string, V>;
+}
+    `.trim()
+  );
+
+  await moduleFile.save();
   return Promise.resolve();
 }

use-cases/build/sharedProject.ts

@@ -0,0 +1,48 @@
+import fs from "fs/promises";
+import path from "path";
+import url from "url";
+
+import {
+  ModuleKind,
+  ModuleResolutionKind,
+  Project,
+  type ProjectOptions,
+  ScriptTarget,
+  SourceFile,
+} from "ts-morph";
+
+const TSC_CONFIG: ProjectOptions = {
+  "compilerOptions": {
+    "lib": ["es2022"],
+    "module": ModuleKind.ESNext,
+    "target": ScriptTarget.ESNext,
+    "moduleResolution": ModuleResolutionKind.NodeNext,
+    "sourceMap": true,
+    "declaration": true,
+  },
+  skipAddingFilesFromTsConfig: true,
+  skipFileDependencyResolution: true,
+};
+
+export const stageDir = path.normalize(path.join(url.fileURLToPath(import.meta.url), "../../"));
+export const distDir = path.join(stageDir, "dist");
+
+export const project = new Project(TSC_CONFIG);
+
+export function getFullPath(pathToLocalFile: string): string {
+  return path.join(stageDir, "dist", pathToLocalFile);
+}
+
+export async function removeDistFile(
+  pathToLocalFile: string
+): Promise<void>
+{
+  await fs.rm(getFullPath(pathToLocalFile), { force: true, recursive: true });
+}
+
+export function getExistingSourceFile(
+  absolutePathToFile: string
+): SourceFile
+{
+  return project.getSourceFile(absolutePathToFile) ?? project.addSourceFileAtPath(absolutePathToFile);
+}

use-cases/dist/StringStringMap.ts

@@ -0,0 +1,18 @@
+interface StringStringKey {
+  readonly firstKey: string,
+  readonly secondKey: string
+}
+
+export default class StringStringMap<V> {
+  static #hashKeys(firstKey: string, secondKey: string): string {
+    return JSON.stringify({firstKey, secondKey});
+  }
+
+  static #parseKeys(hashedKey: string): [string, string]
+  {
+    const { firstKey, secondKey } = JSON.parse(hashedKey) as StringStringKey;
+    return [firstKey, secondKey];
+  }
+
+  readonly #hashMap = new Map<string, V>;
+}