[Python/JS/TS] Codegen SizeOf method for structs (#6136)

* [Python] Codegen SizeOf classmethod for structs

This codegens a `SizeOf()` classmethod for all structs since we can't
determine the size of a FlatBuffer generated struct from Python otherwise.

* [JS/TS] Codegen sizeOf static method for structs

This codegens a `sizeOf()` static method for all structs since we can't
determine the size of a FlatBuffer generated struct from JavaScript or
TypeScript otherwise.

5 files changed, 20 insertions, 0 deletions

diff --git a/tests/MyGame/Example/Ability.py b/tests/MyGame/Example/Ability.py
index 2cc916bd..e57dfd74 100644
--- a/tests/MyGame/Example/Ability.py
+++ b/tests/MyGame/Example/Ability.py
@@ -9,6 +9,10 @@ np = import_numpy()
 class Ability(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def SizeOf(cls):
+        return 8
+
     # Ability
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
diff --git a/tests/MyGame/Example/ArrayStruct.py b/tests/MyGame/Example/ArrayStruct.py
index 50f136df..c80bf688 100644
--- a/tests/MyGame/Example/ArrayStruct.py
+++ b/tests/MyGame/Example/ArrayStruct.py
@@ -9,6 +9,10 @@ np = import_numpy()
 class ArrayStruct(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def SizeOf(cls):
+        return 160
+
     # ArrayStruct
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
diff --git a/tests/MyGame/Example/NestedStruct.py b/tests/MyGame/Example/NestedStruct.py
index a66cee01..a9db014f 100644
--- a/tests/MyGame/Example/NestedStruct.py
+++ b/tests/MyGame/Example/NestedStruct.py
@@ -9,6 +9,10 @@ np = import_numpy()
 class NestedStruct(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def SizeOf(cls):
+        return 32
+
     # NestedStruct
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
diff --git a/tests/MyGame/Example/Test.py b/tests/MyGame/Example/Test.py
index 576a656e..8357ec20 100644
--- a/tests/MyGame/Example/Test.py
+++ b/tests/MyGame/Example/Test.py
@@ -9,6 +9,10 @@ np = import_numpy()
 class Test(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def SizeOf(cls):
+        return 4
+
     # Test
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)
diff --git a/tests/MyGame/Example/Vec3.py b/tests/MyGame/Example/Vec3.py
index 5c91a7d3..69cd511f 100644
--- a/tests/MyGame/Example/Vec3.py
+++ b/tests/MyGame/Example/Vec3.py
@@ -9,6 +9,10 @@ np = import_numpy()
 class Vec3(object):
     __slots__ = ['_tab']
 
+    @classmethod
+    def SizeOf(cls):
+        return 32
+
     # Vec3
     def Init(self, buf, pos):
         self._tab = flatbuffers.table.Table(buf, pos)