Reverts the public Memory.Pages API (#2174)

Signed-off-by: Takeshi Yoneda <[email protected]>

Author: mathetake

api/wasm.go

@@ -565,17 +565,12 @@ type Memory interface {
 	// # Notes
 	//
 	//   - This overflows (returns zero) if the memory has the maximum 65536 pages.
-	//   - Use Pages() to handle this corner case.
+	// 	   As a workaround until wazero v2 to fix the return type, use Grow(0) to obtain the current pages and
+	//     multiply by 65536.
 	//
 	// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#-hrefsyntax-instr-memorymathsfmemorysize%E2%91%A0
 	Size() uint32
 
-	// Pages returns the number of pages in the memory. 1 Page corresponds to 65536 bytes,
-	// which is called "Page Size" in WebAssembly.
-	//
-	// See https://www.w3.org/TR/2019/REC-wasm-core-1-20191205/#memory-instances%E2%91%A0
-	Pages() (pages uint32)
-
 	// Grow increases memory by the delta in pages (65536 bytes per page).
 	// The return val is the previous memory size in pages, or false if the
 	// delta was ignored as it exceeds MemoryDefinition.Max.

internal/wasm/memory_test.go

@@ -68,6 +68,11 @@ func TestMemoryInstance_Grow_Size(t *testing.T) {
 			require.Equal(t, uint32(5), res)
 			require.Equal(t, uint32(9), m.Pages())
 
+			res, ok = m.Grow(0)
+			require.True(t, ok)
+			require.Equal(t, uint32(9), res)
+			require.Equal(t, uint32(9), m.Pages())
+
 			// At this point, the page size equal 9,
 			// so trying to grow two pages should result in failure.
 			_, ok = m.Grow(2)