All files / WRITE/1-Write Write.ts

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
485x
485x
 
 
 
 
948x
265x
 
 
 
 
 
31x
 
 
 
 
2x
2x
 
 
 
 
 
import { dirname } from "node:path";
 
import IFileSystem from "../../types/IFileSystem";
 
/**
 * 3.1 Write: the only module that changes the filesystem (#1653, carrying
 * #1451 box 1).
 *
 * Every file written, directory created, file deleted and file moved goes
 * through here, and through the port the host injected. Reads go through the
 * port directly, since reading changes nothing. A path is decided before it
 * arrives: naming an output never creates its directory, and writing it does.
 * `write-confined-to-3-1.test.ts` holds that no other module calls the port's
 * mutating methods. The one exception is the port's own `withTempFile`: a
 * scratch file an external tool reads, removed before the call returns, so
 * not output (see `IFileSystem`).
 */
class Write {
  /** Write `content` to `path`, creating its directory first. */
  static file(fs: IFileSystem, path: string, content: string): void {
    Write.directory(fs, dirname(path));
    fs.writeFile(path, content);
  }
 
  /** Create `path` and its parents, if it does not exist yet. */
  static directory(fs: IFileSystem, path: string): void {
    if (!fs.exists(path)) {
      fs.mkdir(path, { recursive: true });
    }
  }
 
  /** Delete the file at `path`. */
  static remove(fs: IFileSystem, path: string): void {
    fs.unlink(path);
  }
 
  /** Move the file at `from` to `to`, creating `to`'s directory first. */
  static move(fs: IFileSystem, from: string, to: string): void {
    Write.directory(fs, dirname(to));
    fs.rename(from, to);
  }
}
 
export default Write;