feat(fs): support read-only and read-write file systems

packages/fs/src/__test__/fs.abstraction.test.ts

@@ -19,8 +19,35 @@ o.spec('FileSystemAbstraction', () => {
  const fakeUnknown = new FakeSystem('unknown');
  fsa.register('', fakeUnknown);
 
- o(fsa.get('fake://foo').protocol).equals('fake');
- o(fsa.get('fake:/foo').protocol).equals('unknown');
+ o(fsa.get('fake://foo', 'r').protocol).equals('fake');
+ o(fsa.get('fake:/foo', 'r').protocol).equals('unknown');
+ });
+
+ o('should register filesystems as rw', () => {
+ const fsa = new FileSystemAbstraction();
+
+ const fakeLocal = new FakeSystem('fake');
+ fsa.register('fake://', fakeLocal);
+ o(fsa.get('fake://foo', 'rw').protocol).equals('fake');
+ });
+
+ o('should not return a read only filesystem when wanting to write', () => {
+ const fsa = new FileSystemAbstraction();
+
+ const fakeLocal = new FakeSystem('fake');
+ fsa.register('fake://', fakeLocal, 'r');
+ o(() => fsa.get('fake://foo', 'rw')).throws(Error);
+ });
+
+ o('should allow read and read-write file systems to be registered', () => {
+ const fsa = new FileSystemAbstraction();
+
+ const fakeR = new FakeSystem('r');
+ const fakeRw = new FakeSystem('rw');
+
+ fsa.register('fake://', fakeR, 'r');
+ fsa.register('fake://', fakeRw, 'rw');
+ o(fsa.get('fake://foo', 'rw').protocol).equals('rw');
  });
 
  o('should find file systems in order they were registered', () => {
@@ -31,9 +58,9 @@ o.spec('FileSystemAbstraction', () => {
  fsa.register('fake://', fakeA);
  fsa.register('fake://some-prefix-string/', fakeB);
 
- o(fsa.get('fake://foo').protocol).equals('fake');
- o(fsa.get('fake://some-prefix-string/').protocol).equals('fakeSpecific');
- o(fsa.get('fake://some-prefix-string/some-key').protocol).equals('fakeSpecific');
+ o(fsa.get('fake://foo', 'r').protocol).equals('fake');
+ o(fsa.get('fake://some-prefix-string/', 'r').protocol).equals('fakeSpecific');
+ o(fsa.get('fake://some-prefix-string/some-key', 'r').protocol).equals('fakeSpecific');
  });
 
  o('should order file systems by length', () => {
@@ -44,9 +71,9 @@ o.spec('FileSystemAbstraction', () => {
  fsa.register('fake://some-prefix-string/', fakeB);
  fsa.register('fake://', fakeA);
 
- o(fsa.get('fake://foo').protocol).equals('fake');
- o(fsa.get('fake://some-prefix-string/').protocol).equals('fakeSpecific');
- o(fsa.get('fake://some-prefix-string/some-key').protocol).equals('fakeSpecific');
+ o(fsa.get('fake://foo', 'r').protocol).equals('fake');
+ o(fsa.get('fake://some-prefix-string/', 'r').protocol).equals('fakeSpecific');
+ o(fsa.get('fake://some-prefix-string/some-key', 'r').protocol).equals('fakeSpecific');
  });
 
  o('should replace file systems when registering duplicates', () => {

packages/fs/src/fs.abstraction.ts

@@ -18,33 +18,37 @@ function isRecord(obj: unknown): obj is Record<string, unknown> {
  return obj.constructor === Object;
 }
 
+export type Flag = FlagRead | FlagReadWrite;
+export type FlagRead = 'r';
+export type FlagReadWrite = 'rw';
+
 export class FileSystemAbstraction implements FileSystem {
  protocol = 'abstract';
  /**
  * Is the systems array currently ordered
  * @see FileSystemAbstraction.sortSystems
  */
  private isOrdered = true;
- systems: { path: string; system: FileSystem }[] = [];
+ systems: { path: string; system: FileSystem; flag: Flag }[] = [];
 
  /**
  * Register a file system to a specific path which can then be used with any `fsa` command
  *
  * @example
- * fsa.register('s3://', fsS3)
- * fsa.register('s3://bucket-a/key-a', specificS3)
+ * fsa.register('s3://', fsS3, 'rw')
+ * fsa.register('s3://bucket-a/key-a', specificS3, 'r')
  * fsa.register('http://', fsHttp)
  *
  */
- register(path: string, system: FileSystem): void {
+ register(path: string, system: FileSystem, flag: Flag = 'rw'): void {
  for (let i = 0; i < this.systems.length; i++) {
  const sys = this.systems[i];
- if (sys.path === path) {
- this.systems.splice(i, 1, { path, system });
+ if (sys.path === path && sys.flag === flag) {
+ this.systems.splice(i, 1, { path, system, flag });
  return;
  }
  }
- this.systems.push({ path, system });
+ this.systems.push({ path, system, flag });
  this.isOrdered = false;
  }
 
@@ -56,10 +60,11 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns Content of the file
  */
  read(filePath: string): Promise<Buffer> {
- return this.get(filePath).read(filePath);
+ return this.get(filePath, 'r').read(filePath);
  }
 
- /** Read a file as JSON
+ /**
+ * Read a file as JSON
  * @param filePath file to read
  * @returns JSON Content of the file
  */
@@ -75,7 +80,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns Stream of file contents
  */
  stream(filePath: string): Readable {
- return this.get(filePath).stream(filePath);
+ return this.get(filePath, 'r').stream(filePath);
  }
 
  /**
@@ -89,9 +94,9 @@ export class FileSystemAbstraction implements FileSystem {
  write(filePath: string, buffer: FileWriteTypes, opts?: WriteOptions): Promise<void> {
  if (Array.isArray(buffer) || isRecord(buffer)) {
  const content = JSON.stringify(buffer, null, 2);
- return this.get(filePath).write(filePath, content, { contentType: 'application/json', ...opts });
+ return this.get(filePath, 'rw').write(filePath, content, { contentType: 'application/json', ...opts });
  }
- return this.get(filePath).write(filePath, buffer, opts);
+ return this.get(filePath, 'rw').write(filePath, buffer, opts);
  }
 
  /**
@@ -100,7 +105,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns list of files inside that path
  */
  list(filePath: string, opts?: ListOptions): AsyncGenerator<string> {
- return this.get(filePath).list(filePath, opts);
+ return this.get(filePath, 'r').list(filePath, opts);
  }
 
  /**
@@ -111,7 +116,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns list of files inside that path
  */
  details(filePath: string, opts?: ListOptions): AsyncGenerator<FileInfo> {
- return this.get(filePath).details(filePath, opts);
+ return this.get(filePath, 'r').details(filePath, opts);
  }
 
  /**
@@ -121,7 +126,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns true if file exists, false otherwise
  */
  exists(filePath: string): Promise<boolean> {
- return this.get(filePath)
+ return this.get(filePath, 'r')
  .head(filePath)
  .then((f) => f != null);
  }
@@ -133,7 +138,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns basic information such as file size
  */
  head(filePath: string): Promise<FileInfo | null> {
- return this.get(filePath).head(filePath);
+ return this.get(filePath, 'r').head(filePath);
  }
 
  join = joinUri;
@@ -145,7 +150,7 @@ export class FileSystemAbstraction implements FileSystem {
  * @returns
  */
  source(filePath: string): ChunkSource {
- return this.get(filePath).source(filePath);
+ return this.get(filePath, 'r').source(filePath);
  }
 
  /**
@@ -160,28 +165,18 @@ export class FileSystemAbstraction implements FileSystem {
  }
 
  /** Find the filesystem that would be used for a given path */
- get(filePath: string): FileSystem {
+ get(filePath: string, flag: Flag): FileSystem {
  this.sortSystems();
  for (const cfg of this.systems) {
- if (filePath.startsWith(cfg.path)) return cfg.system;
+ if (filePath.startsWith(cfg.path)) {
+ // If we want to write to the system but only have read-only access
+ if (flag === 'rw' && cfg.flag === 'r') continue;
+ return cfg.system;
+ }
  }
 
  throw new Error(`Unable to find file system for path:${filePath}`);
  }
 }
 
 export const fsa = new FileSystemAbstraction();
-
-// async function main(): Promise<void> {
-// for await (const f of fsa.list('')) {
-// console.log(f);
-// }
-
-// for await (const f of fsa.list('', { details: true })) {
-// console.log(f.path);
-// }
-
-// for await (const f of fsa.list('', { details: false, recursive: false })) {
-// console.log(f.path);
-// }
-// }