feat: Get instance comparison by hand (#1332)

No Symbol.hasInstance voodoo. Babel deserves its name.
ceramicnetwork · Apr 29, 2021 · 8dbdc1b · 8dbdc1b
1 parent 279d729
commit 8dbdc1b
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Showing 6 changed files with 20 additions and 18 deletions.
diff --git a/packages/core/src/ceramic.ts b/packages/core/src/ceramic.ts
@@ -134,7 +134,7 @@ const DEFAULT_NETWORK = Networks.INMEMORY
 
 const normalizeStreamID = (streamId: StreamID | string): StreamID => {
   const streamRef = StreamRef.from(streamId)
-  if (streamRef instanceof StreamID) {
+  if (StreamID.isInstance(streamRef)) {
     return streamRef
   } else {
     throw new Error(`Not StreamID: ${streamRef}`)
@@ -483,7 +483,7 @@ class Ceramic implements CeramicApi {
     opts = { ...DEFAULT_LOAD_OPTS, ...opts };
     const streamRef = StreamRef.from(streamId)
     const base$ = await this._loadStream(streamRef.baseID, opts)
-    if (streamRef instanceof CommitID) {
+    if (CommitID.isInstance(streamRef)) {
       // Here CommitID is requested, let's return stream at specific commit
       const snapshot$ = await this.repository.stateManager.rewind(base$, streamRef)
       return streamFromState<T>(this.context, this._streamHandlers, snapshot$.value)

diff --git a/packages/streamid/src/__tests__/commit-id.test.ts b/packages/streamid/src/__tests__/commit-id.test.ts
@@ -268,9 +268,7 @@ test('#baseID', () => {
 
 test('instanceof', () => {
   const commitId = new CommitID('tile', BASE_CID_STRING, COMMIT_CID_STRING);
-  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-  // @ts-ignore
-  const instanceSpy = jest.spyOn(CommitID, Symbol.hasInstance);
-  expect(commitId instanceof CommitID).toBeTruthy();
+  const instanceSpy = jest.spyOn(CommitID, 'isInstance');
+  expect(CommitID.isInstance(commitId)).toBeTruthy();
   expect(instanceSpy).toBeCalledWith(commitId);
 });
diff --git a/packages/streamid/src/__tests__/stream-id.test.ts b/packages/streamid/src/__tests__/stream-id.test.ts
@@ -194,10 +194,8 @@ describe('#atCommit', () => {
 });
 
 test('instanceof', () => {
-  const streamId = StreamID.fromString(STREAM_ID_STRING)
-  // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-  // @ts-ignore
-  const instanceSpy = jest.spyOn(StreamID, Symbol.hasInstance)
-  expect(streamId instanceof StreamID).toBeTruthy()
-  expect(instanceSpy).toBeCalledWith(streamId)
-})
+  const streamId = StreamID.fromString(STREAM_ID_STRING);
+  const instanceSpy = jest.spyOn(StreamID, 'isInstance');
+  expect(StreamID.isInstance(streamId)).toBeTruthy();
+  expect(instanceSpy).toBeCalledWith(streamId);
+});
diff --git a/packages/streamid/src/commit-id.ts b/packages/streamid/src/commit-id.ts
@@ -109,7 +109,10 @@ export class CommitID implements StreamRef {
   static fromBytes = fromBytes;
   static fromString = fromString;
 
-  static [Symbol.hasInstance](instance: any): boolean {
+  // WORKAROUND. Weird replacement for Symbol.hasInstance due to
+  // this old bug in Babel https://github.com/babel/babel/issues/4452
+  // which is used by CRA, which is widely popular.
+  static isInstance(instance: any): instance is CommitID {
     return typeof instance === 'object' && '_tag' in instance && instance._tag === TAG;
   }
 

diff --git a/packages/streamid/src/stream-id.ts b/packages/streamid/src/stream-id.ts
@@ -56,7 +56,10 @@ export class StreamID implements StreamRef {
   static fromBytes = fromBytes;
   static fromString = fromString;
 
-  static [Symbol.hasInstance](instance: any): boolean {
+  // WORKARDOUND Weird replacement for Symbol.hasInstance due to
+  // this old bug in Babel https://github.com/babel/babel/issues/4452
+  // which is used by CRA, which is widely popular.
+  static isInstance(instance: any): instance is StreamID {
     return typeof instance === 'object' && '_tag' in instance && instance._tag === TAG;
   }
 
@@ -133,7 +136,7 @@ export class StreamID implements StreamRef {
    * Compare equality with another StreamID.
    */
   equals(other: StreamID): boolean {
-    if (other instanceof StreamID) {
+    if (StreamID.isInstance(other)) {
       return this.type === other.type && this.cid.equals(other.cid);
     } else {
       return false;

diff --git a/packages/streamid/src/stream-ref.ts b/packages/streamid/src/stream-ref.ts
@@ -44,9 +44,9 @@ export namespace StreamRef {
    */
   // eslint-disable-next-line no-inner-declarations
   export function from(input: StreamID | CommitID | string | Uint8Array): StreamID | CommitID {
-    if (input instanceof StreamID) {
+    if (StreamID.isInstance(input)) {
       return input;
-    } else if (input instanceof CommitID) {
+    } else if (CommitID.isInstance(input)) {
       return input;
     } else if (input instanceof Uint8Array) {
       // Lazy computation: try CommitID, then StreamID, then complain