From 717b956c609e631fbf84fea133c4cb75f184b182 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Phil=20Pl=C3=BCckthun?= <phil@kitten.sh>
Date: Fri, 13 Mar 2020 19:27:13 +0000
Subject: [PATCH] (graphcache) - Expose data on write and writeOptimistic
 results (#613)

* Expose data on write and writeOptimistic results

* Add changeset
---
 .changeset/metal-otters-mate.md              |  5 +++++
 exchanges/graphcache/src/operations/write.ts | 12 +++++++-----
 2 files changed, 12 insertions(+), 5 deletions(-)
 create mode 100644 .changeset/metal-otters-mate.md

diff --git a/.changeset/metal-otters-mate.md b/.changeset/metal-otters-mate.md
new file mode 100644
index 0000000000..55a0104250
--- /dev/null
+++ b/.changeset/metal-otters-mate.md
@@ -0,0 +1,5 @@
+---
+'@urql/exchange-graphcache': patch
+---
+
+Expose generated result data on writeOptimistic and passthrough data on write operations.
diff --git a/exchanges/graphcache/src/operations/write.ts b/exchanges/graphcache/src/operations/write.ts
index ea8afaa8db..7d46abfbd2 100644
--- a/exchanges/graphcache/src/operations/write.ts
+++ b/exchanges/graphcache/src/operations/write.ts
@@ -37,6 +37,7 @@ import {
 } from './shared';
 
 export interface WriteResult {
+  data: null | Data;
   dependencies: Set<string>;
 }
 
@@ -59,7 +60,7 @@ export const startWrite = (
   data: Data
 ) => {
   const operation = getMainOperation(request.query);
-  const result: WriteResult = { dependencies: getCurrentDependencies() };
+  const result: WriteResult = { data, dependencies: getCurrentDependencies() };
   const operationName = store.rootFields[operation.operation];
 
   const ctx = makeContext(
@@ -75,7 +76,6 @@ export const startWrite = (
   }
 
   writeSelection(ctx, operationName, getSelectionSet(operation), data);
-
   return result;
 };
 
@@ -87,7 +87,10 @@ export const writeOptimistic = (
   initDataState(store.data, key, true);
 
   const operation = getMainOperation(request.query);
-  const result: WriteResult = { dependencies: getCurrentDependencies() };
+  const result: WriteResult = {
+    data: makeDict(),
+    dependencies: getCurrentDependencies(),
+  };
   const operationName = store.rootFields[operation.operation];
 
   invariant(
@@ -110,8 +113,7 @@ export const writeOptimistic = (
     true
   );
 
-  const data = makeDict();
-  writeSelection(ctx, operationName, getSelectionSet(operation), data);
+  writeSelection(ctx, operationName, getSelectionSet(operation), result.data!);
   clearDataState();
   return result;
 };