refactor all internal module imports to use fully-specified paths (wi…

…th extensions)

- use the '.js' (*not* '.ts') extension to force correct fully specified `tsc` output

# Discussion

Browsers/ESM/Deno require fully specified import paths/URLs and don't perform any
extension substitution "magic" when searching for the import file. `tsc` does not
and will likely *never* change the emitted JS code [^1], including rewriting import
paths/URLs. So, the for `tsc` compilation to produce working code these targets, a
fully specified path/URL must be used in the '.ts' source code.

As of TypeScript 2.0, import paths using the '.js' extension as a replacement for
'.ts' are resolved correctly in the compiled code [^2]. The `rollup` bundler is also
noted to support the same construction [^3].

So, the most compatible way construction is to use fully specified import paths which
replace the trailing '.ts' with '.js'. Odd, yes, but it's the best working practice.

# refs

[1]: microsoft/TypeScript#16577 (comment)
[2]: microsoft/TypeScript#16577 (comment)
[3]: microsoft/TypeScript#16577 (comment)

src/index.ts

@@ -1,6 +1,6 @@
 // spell-checker:ignore maint rivy
-import { Adapt, OSPaths } from './lib/OSPaths';
-import { adapter } from './platform-adapters/node';
+import { Adapt, OSPaths } from './lib/OSPaths.js';
+import { adapter } from './platform-adapters/node.js';
 
 const default_: OSPaths = Adapt(adapter).OSPaths;
 

src/lib/OSPaths.ts

@@ -1,6 +1,6 @@
 // # spell-checker:ignore AllUsersProfile HomeDrive HomePath LocalAppData UserProfile WinDir falsey
 
-import { Platform } from '../platform-adapters/_base';
+import { Platform } from '../platform-adapters/_base.js';
 
 /** Determine common OS/platform paths (home, temp, ...) */
 type OSPaths = {

src/platform-adapters/node.ts

@@ -1,7 +1,7 @@
 import * as os from 'os';
 import * as path from 'path';
 
-import { Platform } from './_base';
+import { Platform } from './_base.js';
 
 export const adapter: Platform.Adapter = {
 	env: {