feat: Include dockey in doc exists err (#1558)

## Relevant issue(s)

Resolves #1557

## Description

Includes the dockey in the doc exists err, and the doc deleted error.

db/collection.go

@@ -653,10 +653,10 @@ func (c *collection) create(ctx context.Context, txn datastore.Txn, doc *client.
 		return err
 	}
 	if exists {
-		return ErrDocumentAlreadyExists
+		return NewErrDocumentAlreadyExists(primaryKey.DocKey)
 	}
 	if isDeleted {
-		return ErrDocumentDeleted
+		return NewErrDocumentDeleted(primaryKey.DocKey)
 	}
 
 	// write value object marker if we have an empty doc
@@ -696,7 +696,7 @@ func (c *collection) Update(ctx context.Context, doc *client.Document) error {
 		return client.ErrDocumentNotFound
 	}
 	if isDeleted {
-		return ErrDocumentDeleted
+		return NewErrDocumentDeleted(primaryKey.DocKey)
 	}
 
 	err = c.update(ctx, txn, doc)
@@ -886,7 +886,7 @@ func (c *collection) Delete(ctx context.Context, key client.DocKey) (bool, error
 		return false, client.ErrDocumentNotFound
 	}
 	if isDeleted {
-		return false, ErrDocumentDeleted
+		return false, NewErrDocumentDeleted(primaryKey.DocKey)
 	}
 
 	err = c.applyDelete(ctx, txn, primaryKey)

db/collection_delete.go

@@ -239,7 +239,7 @@ func (c *collection) applyDelete(
 		return client.ErrDocumentNotFound
 	}
 	if isDeleted {
-		return ErrDocumentDeleted
+		return NewErrDocumentDeleted(key.DocKey)
 	}
 
 	dsKey := key.ToDataStoreKey()

db/errors.go

@@ -35,6 +35,8 @@ const (
 	errInvalidCRDTType               string = "only default or LWW (last writer wins) CRDT types are supported"
 	errCannotDeleteField             string = "deleting an existing field is not supported"
 	errFieldKindNotFound             string = "no type found for given name"
+	errDocumentAlreadyExists         string = "a document with the given dockey already exists"
+	errDocumentDeleted               string = "a document with the given dockey has been deleted"
 )
 
 var (
@@ -57,8 +59,8 @@ var (
 	ErrMergeSubTypeNotSupported = errors.New("merge doesn't support sub types yet")
 	ErrInvalidFilter            = errors.New("invalid filter")
 	ErrInvalidOpPath            = errors.New("invalid patch op path")
-	ErrDocumentAlreadyExists    = errors.New("a document with the given dockey already exists")
-	ErrDocumentDeleted          = errors.New("a document with the given dockey has been deleted")
+	ErrDocumentAlreadyExists    = errors.New(errDocumentAlreadyExists)
+	ErrDocumentDeleted          = errors.New(errDocumentDeleted)
 	ErrUnknownCRDTArgument      = errors.New("invalid CRDT arguments")
 	ErrUnknownCRDT              = errors.New("unknown crdt")
 	ErrSchemaFirstFieldDocKey   = errors.New("collection schema first field must be a DocKey")
@@ -214,3 +216,17 @@ func NewErrCannotDeleteField(name string, id client.FieldID) error {
 		errors.NewKV("ID", id),
 	)
 }
+
+func NewErrDocumentAlreadyExists(dockey string) error {
+	return errors.New(
+		errDocumentAlreadyExists,
+		errors.NewKV("DocKey", dockey),
+	)
+}
+
+func NewErrDocumentDeleted(dockey string) error {
+	return errors.New(
+		errDocumentDeleted,
+		errors.NewKV("DocKey", dockey),
+	)
+}

tests/integration/mutation/simple/create/simple_test.go

@@ -93,7 +93,7 @@ func TestMutationCreateSimpleDoesNotCreateDocGivenDuplicate(t *testing.T) {
 				}`,
 			},
 		},
-		ExpectedError: "a document with the given dockey already exists",
+		ExpectedError: "a document with the given dockey already exists. DocKey: ",
 	}
 
 	simpleTests.ExecuteTestCase(t, test)