change to ECMAScript module from commonJS

jest.config.ts

@@ -0,0 +1,15 @@
+// jest.config.ts
+import { createDefaultEsmPreset, type JestConfigWithTsJest } from 'ts-jest'
+
+const defaultEsmPreset = createDefaultEsmPreset()
+
+const jestConfig: JestConfigWithTsJest = {
+  // [...]
+  ...defaultEsmPreset,
+  moduleNameMapper: {
+    '^(\\.{1,2}/.*)\\.js$': '$1',
+  },
+
+}
+
+export default jestConfig

package.json

@@ -8,7 +8,7 @@
     "private": false,
     "scripts": {
         "build": "tsc",
-        "test": "testyts",
+        "test": "jest",
         "doc": "typedoc src/main/ts/TSOFA.ts",
         "eslint": "eslint ."
     },
@@ -42,7 +42,8 @@
         "eslint-plugin-jsdoc": "^46.8.1",
         "eslint-plugin-prefer-arrow": "^1.2.3",
         "globals": "^15.9.0",
-        "testyts": "^1.5.0",
+        "jest": "^29.7.0",
+        "ts-jest": "^29.2.5",
         "ts-node": "^10.9.1",
         "typedoc": "^0.25.6",
         "typescript": "^5.2.2",

src/main/ts/TSOFA.ts

@@ -1,5 +1,5 @@
- import { TSOFAIllegalParameter } from "./TSOFAIllegalParameter";
- import { TSOFAInternalError } from "./TSOFAInternalError";
+ import { TSOFAIllegalParameter } from "./TSOFAIllegalParameter.js";
+ import { TSOFAInternalError } from "./TSOFAInternalError.js";
     /**
      * Typescript implementation of Standards of Fundamental Astronomy. <a href="http://www.iausofa.org/">http://www.iausofa.org/</a>
      * 

tsconfig.json

@@ -1,12 +1,15 @@
 {
   "$schema": "https://json.schemastore.org/tsconfig",
   "compilerOptions": {
-    "module": "commonjs",
-    "target": "es6",
+    "module": "ESNext",
+    "target": "ES2020",
     "declaration": true,
     "sourceMap": true,
+    "declarationMap": true,
+    "esModuleInterop": true,
+    "strict": false,
+    "moduleResolution": "Node",
     "experimentalDecorators": true,
-    "lib": [ "es6" ] ,  
     "outDir": "./dist"
   },
   "include": [