From 4f5ee37ac96eba10fd5b31be09b9599902386c44 Mon Sep 17 00:00:00 2001
From: Yannick Assogba <yassogba@google.com>
Date: Thu, 10 Sep 2020 16:17:45 -0400
Subject: [PATCH 1/3] make tensor instanceof more robust

---
 tfjs-core/src/tensor.ts | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/tfjs-core/src/tensor.ts b/tfjs-core/src/tensor.ts
index c9c2d68ff01..af7e260dfbf 100644
--- a/tfjs-core/src/tensor.ts
+++ b/tfjs-core/src/tensor.ts
@@ -292,7 +292,8 @@ export class Tensor<R extends Rank = Rank> {
     return opHandler.buffer(this.shape, this.dtype as D, vals);
   }
 
-  /** Returns a `tf.TensorBuffer` that holds the underlying data.
+  /**
+   * Returns a `tf.TensorBuffer` that holds the underlying data.
    * @doc {heading: 'Tensors', subheading: 'Classes'}
    */
   bufferSync<D extends DataType = 'float32'>(): TensorBuffer<R, D> {
@@ -411,7 +412,8 @@ export class Tensor<R extends Rank = Rank> {
     return opHandler.print(this, verbose);
   }
 
-  /** Returns a copy of the tensor. See `tf.clone` for details.
+  /**
+   * Returns a copy of the tensor. See `tf.clone` for details.
    * @doc {heading: 'Tensors', subheading: 'Classes'}
    */
   clone<T extends Tensor>(this: T): T {
@@ -441,8 +443,13 @@ export class Tensor<R extends Rank = Rank> {
 }
 Object.defineProperty(Tensor, Symbol.hasInstance, {
   value: (instance: Tensor) => {
-    return !!instance && instance.dataId != null && instance.shape != null &&
-        instance.dtype != null;
+    // Implementation note: we should use properties of the object will be
+    // defined before the constructor body has finished executing (methods).
+    // This is because when this code is transpiled by babel, babel will call
+    // classCallCheck before the constructor body is run.
+    // See https://github.com/tensorflow/tfjs/issues/3384 for backstory.
+    return !!instance && instance.data != null && instance.dataSync != null &&
+        instance.throwIfDisposed != null;
   }
 });
 

From ffbc0aa8b7ea1fcd0b629aa15f7347a8cfc57773 Mon Sep 17 00:00:00 2001
From: Yannick Assogba <yassogba@google.com>
Date: Thu, 10 Sep 2020 17:06:46 -0400
Subject: [PATCH 2/3] save

---
 tfjs-core/src/tensor_test.ts   | 5 -----
 tfjs-core/src/variable_test.ts | 5 -----
 2 files changed, 10 deletions(-)

diff --git a/tfjs-core/src/tensor_test.ts b/tfjs-core/src/tensor_test.ts
index 207845fb35f..ae95b38ffd1 100644
--- a/tfjs-core/src/tensor_test.ts
+++ b/tfjs-core/src/tensor_test.ts
@@ -2208,11 +2208,6 @@ describeWithFlags('x instanceof Tensor', ALL_ENVS, () => {
     expect(t instanceof Tensor).toBe(true);
   });
 
-  it('x: Tensor-like', () => {
-    const t = {shape: [2], dtype: 'float32', dataId: {}};
-    expect(t instanceof Tensor).toBe(true);
-  });
-
   it('x: other object, fails', () => {
     const t = {something: 'else'};
     expect(t instanceof Tensor).toBe(false);
diff --git a/tfjs-core/src/variable_test.ts b/tfjs-core/src/variable_test.ts
index a3fac13c02a..80763bb0320 100644
--- a/tfjs-core/src/variable_test.ts
+++ b/tfjs-core/src/variable_test.ts
@@ -220,11 +220,6 @@ describeWithFlags('x instanceof Variable', ALL_ENVS, () => {
     expect(t instanceof Variable).toBe(true);
   });
 
-  it('x: Variable-like', () => {
-    const t = {assign: () => {}, shape: [2], dtype: 'float32', dataId: {}};
-    expect(t instanceof Variable).toBe(true);
-  });
-
   it('x: other object, fails', () => {
     const t = {something: 'else'};
     expect(t instanceof Variable).toBe(false);

From 8195fafbac856a840aa97fad676d80d7054d0785 Mon Sep 17 00:00:00 2001
From: Yannick Assogba <yassogba@google.com>
Date: Thu, 10 Sep 2020 19:20:08 -0400
Subject: [PATCH 3/3] save

---
 tfjs-core/src/tensor.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tfjs-core/src/tensor.ts b/tfjs-core/src/tensor.ts
index af7e260dfbf..e1c09828676 100644
--- a/tfjs-core/src/tensor.ts
+++ b/tfjs-core/src/tensor.ts
@@ -443,7 +443,7 @@ export class Tensor<R extends Rank = Rank> {
 }
 Object.defineProperty(Tensor, Symbol.hasInstance, {
   value: (instance: Tensor) => {
-    // Implementation note: we should use properties of the object will be
+    // Implementation note: we should use properties of the object that will be
     // defined before the constructor body has finished executing (methods).
     // This is because when this code is transpiled by babel, babel will call
     // classCallCheck before the constructor body is run.