From 448c203e137ef9b1e598a851c2bcdf8458670277 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Fri, 31 Mar 2023 17:41:51 +0200
Subject: [PATCH 01/13] Add tests for handling different return types from
 custom handlers

---
 test/resources/custom-handlers/server.js      |   6 +
 .../custom-handlers/srv/return-types.cds      |  21 ++
 .../custom-handlers/srv/return-types.js       |   9 +
 test/tests/custom-handlers.test.js            | 246 ++++++++++++++++++
 4 files changed, 282 insertions(+)
 create mode 100644 test/resources/custom-handlers/server.js
 create mode 100644 test/resources/custom-handlers/srv/return-types.cds
 create mode 100644 test/resources/custom-handlers/srv/return-types.js
 create mode 100644 test/tests/custom-handlers.test.js

diff --git a/test/resources/custom-handlers/server.js b/test/resources/custom-handlers/server.js
new file mode 100644
index 00000000..6808b2bb
--- /dev/null
+++ b/test/resources/custom-handlers/server.js
@@ -0,0 +1,6 @@
+const cds = require('@sap/cds')
+const path = require('path')
+
+cds.env.protocols = {
+  graphql: { path: '/graphql', impl: path.join(__dirname, '../../../index.js') }
+}
\ No newline at end of file
diff --git a/test/resources/custom-handlers/srv/return-types.cds b/test/resources/custom-handlers/srv/return-types.cds
new file mode 100644
index 00000000..663cb32c
--- /dev/null
+++ b/test/resources/custom-handlers/srv/return-types.cds
@@ -0,0 +1,21 @@
+service ReturnTypesService {
+  entity Integer {
+    key id     : UUID;
+        string : cds.String;
+  }
+
+  entity String {
+    key id     : UUID;
+        string : cds.String;
+  }
+
+  entity Object {
+    key id     : UUID;
+        string : cds.String;
+  }
+
+  entity Array {
+    key id     : UUID;
+        string : cds.String;
+  }
+}
diff --git a/test/resources/custom-handlers/srv/return-types.js b/test/resources/custom-handlers/srv/return-types.js
new file mode 100644
index 00000000..586c1f9d
--- /dev/null
+++ b/test/resources/custom-handlers/srv/return-types.js
@@ -0,0 +1,9 @@
+module.exports = srv => {
+  const string = 'foo'
+  const id = '0557a188-326e-4dcb-999b-e1acf7979fa3'
+
+  srv.on('*', 'Integer', () => 999)
+  srv.on('*', 'String', () => string)
+  srv.on('*', 'Object', () => ({ id, string }))
+  srv.on('*', 'Array', () => [{ id, string }, { id, string }])
+}
\ No newline at end of file
diff --git a/test/tests/custom-handlers.test.js b/test/tests/custom-handlers.test.js
new file mode 100644
index 00000000..75cb93d9
--- /dev/null
+++ b/test/tests/custom-handlers.test.js
@@ -0,0 +1,246 @@
+describe('graphql - custom handlers', () => {
+  const cds = require('@sap/cds/lib')
+  const path = require('path')
+  const { gql } = require('../util')
+
+  const { axios, POST } = cds.test(path.join(__dirname, '../resources/custom-handlers'))
+  // Prevent axios from throwing errors for non 2xx status codes
+  axios.defaults.validateStatus = false
+
+  describe('Handling of different return types returned by custom handlers', () => {
+    const id = '0557a188-326e-4dcb-999b-e1acf7979fa3'
+    const string = 'foo'
+
+    test('Integer, String, Object, and Array returned for CREATE custom handler', async () => {
+      const query = gql`
+        mutation {
+          ReturnTypesService {
+            Integer {
+              create(input: {}) {
+                id
+                string
+              }
+            }
+            String {
+              create(input: {}) {
+                id
+                string
+              }
+            }
+            Object {
+              create(input: {}) {
+                id
+                string
+              }
+            }
+            Array {
+              create(input: {}) {
+                id
+                string
+              }
+            }
+          }
+        }
+      `
+      const data = {
+        ReturnTypesService: {
+          Integer: {
+            create: null
+          },
+          String: {
+            create: null
+          },
+          Object: {
+            create: [{ id, string }]
+          },
+          Array: {
+            create: [
+              { id, string },
+              { id, string }
+            ]
+          }
+        }
+      }
+      const errors = [
+        {
+          locations: [{ column: 15, line: 5 }],
+          message: 'Expected Iterable, but did not find one for field "ReturnTypesService_Integer_input.create".',
+          path: ['ReturnTypesService', 'Integer', 'create']
+        },
+        {
+          locations: [{ column: 15, line: 11 }],
+          message: 'Expected Iterable, but did not find one for field "ReturnTypesService_String_input.create".',
+          path: ['ReturnTypesService', 'String', 'create']
+        }
+      ]
+      const response = await POST('/graphql', { query })
+      expect(response.data).toEqual({ data, errors })
+    })
+
+    test('Integer, String, Object, and Array returned for READ custom handler', async () => {
+      const query = gql`
+        query {
+          ReturnTypesService {
+            Integer {
+              nodes {
+                id
+                string
+              }
+            }
+            String {
+              nodes {
+                id
+                string
+              }
+            }
+            Object {
+              nodes {
+                id
+                string
+              }
+            }
+            Array {
+              nodes {
+                id
+                string
+              }
+            }
+          }
+        }
+      `
+      const data = {
+        ReturnTypesService: {
+          Integer: {
+            nodes: null
+          },
+          String: {
+            nodes: null
+          },
+          Object: {
+            nodes: [{ id, string }]
+          },
+          Array: {
+            nodes: [
+              { id, string },
+              { id, string }
+            ]
+          }
+        }
+      }
+      const response = await POST('/graphql', { query })
+      expect(response.data).toEqual({ data })
+    })
+
+    test('Integer, String, Object, and Array returned for UPDATE custom handler', async () => {
+      const query = gql`
+        mutation {
+          ReturnTypesService {
+            Integer {
+              update(filter: [], input: {}) {
+                id
+                string
+              }
+            }
+            String {
+              update(filter: [], input: {}) {
+                id
+                string
+              }
+            }
+            Object {
+              update(filter: [], input: {}) {
+                id
+                string
+              }
+            }
+            Array {
+              update(filter: [], input: {}) {
+                id
+                string
+              }
+            }
+          }
+        }
+      `
+      const data = {
+        ReturnTypesService: {
+          Integer: {
+            update: null
+          },
+          String: {
+            update: null
+          },
+          Object: {
+            update: [{ id, string }]
+          },
+          Array: {
+            update: [
+              { id, string },
+              { id, string }
+            ]
+          }
+        }
+      }
+      const errors = [
+        {
+          locations: [{ column: 15, line: 5 }],
+          message: 'Expected Iterable, but did not find one for field "ReturnTypesService_Integer_input.update".',
+          path: ['ReturnTypesService', 'Integer', 'update']
+        },
+        {
+          locations: [{ column: 15, line: 11 }],
+          message: 'Expected Iterable, but did not find one for field "ReturnTypesService_String_input.update".',
+          path: ['ReturnTypesService', 'String', 'update']
+        }
+      ]
+      const response = await POST('/graphql', { query })
+      expect(response.data).toEqual({ data, errors })
+    })
+
+    test('Integer, String, Object, and Array returned for DELETE custom handler', async () => {
+      const query = gql`
+        mutation {
+          ReturnTypesService {
+            Integer {
+              delete(filter: [])
+            }
+            String {
+              delete(filter: [])
+            }
+            Object {
+              delete(filter: [])
+            }
+            Array {
+              delete(filter: [])
+            }
+          }
+        }
+      `
+      const data = {
+        ReturnTypesService: {
+          Integer: {
+            delete: 999
+          },
+          String: {
+            delete: null
+          },
+          Object: {
+            delete: 1
+          },
+          Array: {
+            delete: 2
+          }
+        }
+      }
+      const errors = [
+        {
+          locations: [{ column: 15, line: 8 }],
+          message: 'Int cannot represent non-integer value: "foo"',
+          path: ['ReturnTypesService', 'String', 'delete']
+        }
+      ]
+      const response = await POST('/graphql', { query })
+      expect(response.data).toEqual({ data, errors })
+    })
+  })
+})

From 73c5dcfb16ed4561633711fadfbd7035ae3d50cb Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Fri, 31 Mar 2023 17:42:05 +0200
Subject: [PATCH 02/13] Fix test description typo

---
 test/tests/concurrency.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/tests/concurrency.test.js b/test/tests/concurrency.test.js
index fd14c010..93ccfc77 100644
--- a/test/tests/concurrency.test.js
+++ b/test/tests/concurrency.test.js
@@ -1,4 +1,4 @@
-describe('graphql resolver concurrency', () => {
+describe('graphql - resolver concurrency', () => {
   const cds = require('@sap/cds/lib')
   const path = require('path')
   const { gql } = require('../util')

From a836929f2b2db6734d39044f850bdedd41f90423 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Fri, 31 Mar 2023 17:43:49 +0200
Subject: [PATCH 03/13] Return 1 for objects and array.length for arrays set in
 delete custom handlers

---
 lib/resolvers/crud/delete.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/resolvers/crud/delete.js b/lib/resolvers/crud/delete.js
index db235697..aaac1533 100644
--- a/lib/resolvers/crud/delete.js
+++ b/lib/resolvers/crud/delete.js
@@ -16,5 +16,9 @@ module.exports = async (service, entity, selection) => {
     else throw e
   }
 
+  // Custom handlers can return non-numeric results for delete
+  if (Array.isArray(result)) return result.length
+  if (typeof result === 'object') return 1
+
   return result
 }

From 26dc385630800549aa5257472a781ecb45e099ed Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Fri, 31 Mar 2023 17:45:11 +0200
Subject: [PATCH 04/13] Only wrap objects in arrays instead of all types in CUD
 resolvers

---
 lib/resolvers/crud/create.js |  2 +-
 lib/resolvers/crud/read.js   |  4 +++-
 lib/resolvers/crud/update.js | 11 ++++++++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/lib/resolvers/crud/create.js b/lib/resolvers/crud/create.js
index 3b98a451..922bfdad 100644
--- a/lib/resolvers/crud/create.js
+++ b/lib/resolvers/crud/create.js
@@ -12,7 +12,7 @@ module.exports = async (service, entity, selection) => {
   query.entries(entries)
 
   const result = await service.run(query)
-  const resultInArray = Array.isArray(result) ? result : [result]
+  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
 
   return formatResult(selection, resultInArray, true)
 }
diff --git a/lib/resolvers/crud/read.js b/lib/resolvers/crud/read.js
index 2a009fb1..d3212901 100644
--- a/lib/resolvers/crud/read.js
+++ b/lib/resolvers/crud/read.js
@@ -27,5 +27,7 @@ module.exports = async (service, entity, selection) => {
 
   const result = await service.run(query)
 
-  return formatResult(selection, result)
+  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
+
+  return formatResult(selection, resultInArray)
 }
diff --git a/lib/resolvers/crud/update.js b/lib/resolvers/crud/update.js
index c9ea4f15..794663cc 100644
--- a/lib/resolvers/crud/update.js
+++ b/lib/resolvers/crud/update.js
@@ -30,8 +30,13 @@ module.exports = async (service, entity, selection) => {
     return tx.run(query)
   })
 
-  // Merge selected fields with updated data
-  const mergedResults = resultBeforeUpdate.map(original => ({ ...original, ...result }))
+  let mergedResults = result
+  if (Array.isArray(resultBeforeUpdate)) {
+    // Merge selected fields with updated data
+    mergedResults = resultBeforeUpdate.map(original => ({ ...original, ...result }))
+  }
 
-  return formatResult(selection, mergedResults, true)
+  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
+
+  return formatResult(selection, resultInArray, true)
 }

From 0979766529886974ca1d871cb6fc1bb26a46adea Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 14:43:48 +0200
Subject: [PATCH 05/13] Use mergedResults instead of result in update

---
 lib/resolvers/crud/update.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/resolvers/crud/update.js b/lib/resolvers/crud/update.js
index 794663cc..277ed8a8 100644
--- a/lib/resolvers/crud/update.js
+++ b/lib/resolvers/crud/update.js
@@ -36,7 +36,8 @@ module.exports = async (service, entity, selection) => {
     mergedResults = resultBeforeUpdate.map(original => ({ ...original, ...result }))
   }
 
-  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
+  const resultInArray =
+    typeof mergedResults === 'object' && !Array.isArray(mergedResults) ? [mergedResults] : mergedResults
 
   return formatResult(selection, resultInArray, true)
 }

From c6a6306c384d69a5c589122e0258e4a162a1068d Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 14:55:45 +0200
Subject: [PATCH 06/13] Use isPlainObject helper instead of typeof object

---
 lib/resolvers/crud/create.js          | 3 ++-
 lib/resolvers/crud/delete.js          | 3 ++-
 lib/resolvers/crud/read.js            | 3 ++-
 lib/resolvers/crud/update.js          | 4 ++--
 lib/resolvers/parse/ast/fromObject.js | 2 +-
 lib/resolvers/parse/ast/result.js     | 2 +-
 lib/resolvers/parse/ast/util/index.js | 3 ---
 lib/resolvers/utils/index.js          | 4 +++-
 8 files changed, 13 insertions(+), 11 deletions(-)
 delete mode 100644 lib/resolvers/parse/ast/util/index.js

diff --git a/lib/resolvers/crud/create.js b/lib/resolvers/crud/create.js
index 922bfdad..fe5a6787 100644
--- a/lib/resolvers/crud/create.js
+++ b/lib/resolvers/crud/create.js
@@ -2,6 +2,7 @@ const { INSERT } = require('@sap/cds/lib').ql
 const { ARGS } = require('../../constants')
 const formatResult = require('../parse/ast/result')
 const { getArgumentByName, astToEntries } = require('../parse/ast2cqn')
+const { isPlainObject } = require('../utils')
 const { entriesStructureToEntityStructure } = require('./utils')
 
 module.exports = async (service, entity, selection) => {
@@ -12,7 +13,7 @@ module.exports = async (service, entity, selection) => {
   query.entries(entries)
 
   const result = await service.run(query)
-  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
+  const resultInArray = isPlainObject(result) && !Array.isArray(result) ? [result] : result
 
   return formatResult(selection, resultInArray, true)
 }
diff --git a/lib/resolvers/crud/delete.js b/lib/resolvers/crud/delete.js
index aaac1533..8724a873 100644
--- a/lib/resolvers/crud/delete.js
+++ b/lib/resolvers/crud/delete.js
@@ -1,6 +1,7 @@
 const { DELETE } = require('@sap/cds/lib').ql
 const { ARGS } = require('../../constants')
 const { getArgumentByName, astToWhere } = require('../parse/ast2cqn')
+const { isPlainObject } = require('../utils')
 
 module.exports = async (service, entity, selection) => {
   let query = DELETE.from(entity)
@@ -18,7 +19,7 @@ module.exports = async (service, entity, selection) => {
 
   // Custom handlers can return non-numeric results for delete
   if (Array.isArray(result)) return result.length
-  if (typeof result === 'object') return 1
+  if (isPlainObject(result)) return 1
 
   return result
 }
diff --git a/lib/resolvers/crud/read.js b/lib/resolvers/crud/read.js
index d3212901..e1465068 100644
--- a/lib/resolvers/crud/read.js
+++ b/lib/resolvers/crud/read.js
@@ -2,6 +2,7 @@ const { SELECT } = require('@sap/cds/lib').ql
 const { ARGS, CONNECTION_FIELDS } = require('../../constants')
 const { getArgumentByName, astToColumns, astToWhere, astToOrderBy, astToLimit } = require('../parse/ast2cqn')
 const formatResult = require('../parse/ast/result')
+const { isPlainObject } = require('../utils')
 
 module.exports = async (service, entity, selection) => {
   const selections = selection.selectionSet.selections
@@ -27,7 +28,7 @@ module.exports = async (service, entity, selection) => {
 
   const result = await service.run(query)
 
-  const resultInArray = typeof result === 'object' && !Array.isArray(result) ? [result] : result
+  const resultInArray = isPlainObject(result) && !Array.isArray(result) ? [result] : result
 
   return formatResult(selection, resultInArray)
 }
diff --git a/lib/resolvers/crud/update.js b/lib/resolvers/crud/update.js
index 277ed8a8..6ebe6ebb 100644
--- a/lib/resolvers/crud/update.js
+++ b/lib/resolvers/crud/update.js
@@ -2,6 +2,7 @@ const { SELECT, UPDATE } = require('@sap/cds/lib').ql
 const { ARGS } = require('../../constants')
 const formatResult = require('../parse/ast/result')
 const { getArgumentByName, astToColumns, astToWhere, astToEntries } = require('../parse/ast2cqn')
+const { isPlainObject } = require('../utils')
 const { entriesStructureToEntityStructure } = require('./utils')
 
 module.exports = async (service, entity, selection) => {
@@ -36,8 +37,7 @@ module.exports = async (service, entity, selection) => {
     mergedResults = resultBeforeUpdate.map(original => ({ ...original, ...result }))
   }
 
-  const resultInArray =
-    typeof mergedResults === 'object' && !Array.isArray(mergedResults) ? [mergedResults] : mergedResults
+  const resultInArray = isPlainObject(mergedResults) && !Array.isArray(mergedResults) ? [mergedResults] : mergedResults
 
   return formatResult(selection, resultInArray, true)
 }
diff --git a/lib/resolvers/parse/ast/fromObject.js b/lib/resolvers/parse/ast/fromObject.js
index fa35feca..02a8a809 100644
--- a/lib/resolvers/parse/ast/fromObject.js
+++ b/lib/resolvers/parse/ast/fromObject.js
@@ -1,5 +1,5 @@
 const { Kind } = require('graphql')
-const { isPlainObject } = require('./util')
+const { isPlainObject } = require('../../utils')
 
 const _nullValue = { kind: Kind.NULL }
 
diff --git a/lib/resolvers/parse/ast/result.js b/lib/resolvers/parse/ast/result.js
index c134e09c..24647e7b 100644
--- a/lib/resolvers/parse/ast/result.js
+++ b/lib/resolvers/parse/ast/result.js
@@ -1,6 +1,6 @@
 const { CONNECTION_FIELDS } = require('../../../constants')
+const { isPlainObject } = require('../../utils')
 const { getPotentiallyNestedNodesSelections } = require('../util')
-const { isPlainObject } = require('./util')
 
 const formatResult = (field, result, skipTopLevelConnection) => {
   const _formatObject = (selections, object) => {
diff --git a/lib/resolvers/parse/ast/util/index.js b/lib/resolvers/parse/ast/util/index.js
deleted file mode 100644
index d7970344..00000000
--- a/lib/resolvers/parse/ast/util/index.js
+++ /dev/null
@@ -1,3 +0,0 @@
-const isPlainObject = value => value !== null && typeof value === 'object' && !Buffer.isBuffer(value)
-
-module.exports = { isPlainObject }
diff --git a/lib/resolvers/utils/index.js b/lib/resolvers/utils/index.js
index 1ac9c375..36e1c586 100644
--- a/lib/resolvers/utils/index.js
+++ b/lib/resolvers/utils/index.js
@@ -1,3 +1,5 @@
+const isPlainObject = value => value !== null && typeof value === 'object' && !Buffer.isBuffer(value)
+
 const _ensureError = error => (error instanceof Error ? error : new Error(error))
 
 const setResponse = async (response, key, value) => {
@@ -8,4 +10,4 @@ const setResponse = async (response, key, value) => {
   }
 }
 
-module.exports = { setResponse }
+module.exports = { isPlainObject, setResponse }

From 7b98a2edf877b26d2fcacd4e57531240cb9f9a1d Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 15:43:34 +0200
Subject: [PATCH 07/13] Add is not array check to isPlainObject helper

---
 lib/resolvers/crud/create.js | 2 +-
 lib/resolvers/crud/delete.js | 2 +-
 lib/resolvers/crud/read.js   | 2 +-
 lib/resolvers/crud/update.js | 2 +-
 lib/resolvers/utils/index.js | 3 ++-
 5 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/resolvers/crud/create.js b/lib/resolvers/crud/create.js
index fe5a6787..25557d96 100644
--- a/lib/resolvers/crud/create.js
+++ b/lib/resolvers/crud/create.js
@@ -13,7 +13,7 @@ module.exports = async (service, entity, selection) => {
   query.entries(entries)
 
   const result = await service.run(query)
-  const resultInArray = isPlainObject(result) && !Array.isArray(result) ? [result] : result
+  const resultInArray = isPlainObject(result) ? [result] : result
 
   return formatResult(selection, resultInArray, true)
 }
diff --git a/lib/resolvers/crud/delete.js b/lib/resolvers/crud/delete.js
index 8724a873..fc239062 100644
--- a/lib/resolvers/crud/delete.js
+++ b/lib/resolvers/crud/delete.js
@@ -18,8 +18,8 @@ module.exports = async (service, entity, selection) => {
   }
 
   // Custom handlers can return non-numeric results for delete
-  if (Array.isArray(result)) return result.length
   if (isPlainObject(result)) return 1
+  if (Array.isArray(result)) return result.length
 
   return result
 }
diff --git a/lib/resolvers/crud/read.js b/lib/resolvers/crud/read.js
index e1465068..a3c338df 100644
--- a/lib/resolvers/crud/read.js
+++ b/lib/resolvers/crud/read.js
@@ -28,7 +28,7 @@ module.exports = async (service, entity, selection) => {
 
   const result = await service.run(query)
 
-  const resultInArray = isPlainObject(result) && !Array.isArray(result) ? [result] : result
+  const resultInArray = isPlainObject(result) ? [result] : result
 
   return formatResult(selection, resultInArray)
 }
diff --git a/lib/resolvers/crud/update.js b/lib/resolvers/crud/update.js
index 6ebe6ebb..c861cc4f 100644
--- a/lib/resolvers/crud/update.js
+++ b/lib/resolvers/crud/update.js
@@ -37,7 +37,7 @@ module.exports = async (service, entity, selection) => {
     mergedResults = resultBeforeUpdate.map(original => ({ ...original, ...result }))
   }
 
-  const resultInArray = isPlainObject(mergedResults) && !Array.isArray(mergedResults) ? [mergedResults] : mergedResults
+  const resultInArray = isPlainObject(mergedResults) ? [mergedResults] : mergedResults
 
   return formatResult(selection, resultInArray, true)
 }
diff --git a/lib/resolvers/utils/index.js b/lib/resolvers/utils/index.js
index 36e1c586..5ea76237 100644
--- a/lib/resolvers/utils/index.js
+++ b/lib/resolvers/utils/index.js
@@ -1,4 +1,5 @@
-const isPlainObject = value => value !== null && typeof value === 'object' && !Buffer.isBuffer(value)
+const isPlainObject = value =>
+  value !== null && typeof value === 'object' && !Array.isArray(value) && !Buffer.isBuffer(value)
 
 const _ensureError = error => (error instanceof Error ? error : new Error(error))
 

From 3aa8900ee97f53176951d45541b14a1268484cf4 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 16:11:32 +0200
Subject: [PATCH 08/13] Improve comment

---
 lib/resolvers/crud/delete.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/resolvers/crud/delete.js b/lib/resolvers/crud/delete.js
index fc239062..b24a80b7 100644
--- a/lib/resolvers/crud/delete.js
+++ b/lib/resolvers/crud/delete.js
@@ -17,7 +17,8 @@ module.exports = async (service, entity, selection) => {
     else throw e
   }
 
-  // Custom handlers can return non-numeric results for delete
+  // The CDS delete query returns the number of deleted entries
+  // However, custom handlers can return non-numeric results for delete
   if (isPlainObject(result)) return 1
   if (Array.isArray(result)) return result.length
 

From 38be8e23c5ae5dad3bb84aa837d446d1df76ecfe Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 17:53:26 +0200
Subject: [PATCH 09/13] Add changelog entries

---
 CHANGELOG.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 132f0985..51e8eb77 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,8 +9,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Delete mutations now return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
+
 ### Changed
 
+- Improved consistency of handling results of different types returned by custom handlers in CRUD resolvers
+
 ### Fixed
 
 ### Removed

From f849a3f4415b4e8da35ed177fd05a31ecd5b5a00 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 18:32:16 +0200
Subject: [PATCH 10/13] Improve changelog entries

---
 CHANGELOG.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51e8eb77..c6b51d5a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,11 +9,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- Delete mutations now return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
-
 ### Changed
 
-- Improved consistency of handling results of different types returned by custom handlers in CRUD resolvers
+- Improved consistency of handling results of different types returned by custom handlers in CRUD resolvers:
+  + Wrap only objects (not primitive types) returned by custom handlers in arrays in Create, Update, and Delete resolvers
+  + Delete mutations now return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
 
 ### Fixed
 

From 72b1e454ab5cb01600df449c9a229ba689e26119 Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Mon, 3 Apr 2023 18:54:25 +0200
Subject: [PATCH 11/13] Return {} instead of [] for no update needed guard
 clause

---
 lib/resolvers/crud/update.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/resolvers/crud/update.js b/lib/resolvers/crud/update.js
index c861cc4f..90031aeb 100644
--- a/lib/resolvers/crud/update.js
+++ b/lib/resolvers/crud/update.js
@@ -27,7 +27,7 @@ module.exports = async (service, entity, selection) => {
   const result = await service.tx(async tx => {
     // read needs to be done before the update, otherwise the where clause might become invalid (case that properties in where clause are updated by the mutation)
     resultBeforeUpdate = await tx.run(queryBeforeUpdate)
-    if (resultBeforeUpdate.length === 0) return []
+    if (resultBeforeUpdate.length === 0) return {}
     return tx.run(query)
   })
 

From 5595c70ff906a5c9be720d0f8ff0386527500a7a Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Tue, 4 Apr 2023 09:59:41 +0200
Subject: [PATCH 12/13] Changelog entry wording

---
 CHANGELOG.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6b51d5a..d12d7409 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,8 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved consistency of handling results of different types returned by custom handlers in CRUD resolvers:
-  + Wrap only objects (not primitive types) returned by custom handlers in arrays in Create, Update, and Delete resolvers
-  + Delete mutations now return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
+  + Wrap only objects (not primitive types) returned by custom handlers in arrays in create, update, and delete resolvers
+  + Delete mutations return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
 
 ### Fixed
 

From ba64049b9259a893a58a8705362435c7cf7781fd Mon Sep 17 00:00:00 2001
From: Marcel Schwarz <marcel.schwarz@sap.com>
Date: Wed, 5 Apr 2023 10:15:33 +0200
Subject: [PATCH 13/13] Fix and improve changelog entries

---
 CHANGELOG.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d12d7409..824578d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,8 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved consistency of handling results of different types returned by custom handlers in CRUD resolvers:
-  + Wrap only objects (not primitive types) returned by custom handlers in arrays in create, update, and delete resolvers
-  + Delete mutations return the length of the array that is returned by a `DELETE` custom handler or 1 if a single object is returned
+  + Wrap only objects (i.e. not primitive types or arrays) returned by custom handlers in arrays in create, read, and update resolvers
+  + Delete mutations return the length of an array that is returned by a `DELETE` custom handler or 1 if a single object is returned
 
 ### Fixed