fix: Correctly return cursor in list method (#127)

* Return hasMore field and null cursor for last page * Fix tests * Improve test coverage
harryzcy · Jul 17, 2022 · a993ff9 · a993ff9
1 parent 04368dc
commit a993ff9
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Showing 3 changed files with 80 additions and 42 deletions.
diff --git a/internal/email/list.go b/internal/email/list.go
@@ -20,6 +20,7 @@ type ListResult struct {
 	Count      int         `json:"count"`
 	Items      []TimeIndex `json:"items"`
 	NextCursor *Cursor     `json:"nextCursor"`
+	HasMore    bool        `json:"hasMore"`
 }
 
 // List lists emails in DynamoDB
@@ -62,18 +63,24 @@ func List(ctx context.Context, api QueryAPI, input ListInput) (*ListResult, erro
 		return nil, err
 	}
 
-	return &ListResult{
-		Count: len(result.items),
-		Items: result.items,
-		NextCursor: &Cursor{
+	var nextCursor *Cursor
+	if result.hasMore {
+		nextCursor = &Cursor{
 			QueryInfo: QueryInfo{
 				Type:  input.Type,
 				Year:  input.Year,
 				Month: input.Month,
 				Order: input.Order,
 			},
 			LastEvaluatedKey: result.lastEvaluatedKey,
-		},
+		}
+	}
+
+	return &ListResult{
+		Count:      len(result.items),
+		Items:      result.items,
+		NextCursor: nextCursor,
+		HasMore:    result.hasMore,
 	}, nil
 }
 

diff --git a/internal/email/list_query.go b/internal/email/list_query.go
@@ -26,6 +26,7 @@ var unmarshalListOfMaps = attributevalue.UnmarshalListOfMaps
 type listQueryResult struct {
 	items            []TimeIndex
 	lastEvaluatedKey map[string]types.AttributeValue
+	hasMore          bool
 }
 
 // listByYearMonth returns a list of emails within a DynamoDB partition.
@@ -73,5 +74,6 @@ func listByYearMonth(ctx context.Context, api QueryAPI, input listQueryInput) (l
 	return listQueryResult{
 		items:            items,
 		lastEvaluatedKey: resp.LastEvaluatedKey,
+		hasMore:          resp.LastEvaluatedKey != nil && len(resp.LastEvaluatedKey) > 0,
 	}, nil
 }
diff --git a/internal/email/list_test.go b/internal/email/list_test.go
@@ -2,6 +2,7 @@ package email
 
 import (
 	"context"
+	"errors"
 	"strconv"
 	"testing"
 	"time"
@@ -30,13 +31,25 @@ func TestList(t *testing.T) {
 								"DateTime":      &types.AttributeValueMemberS{Value: "12-01:01:01"},
 							},
 						},
+						LastEvaluatedKey: map[string]types.AttributeValue{
+							"MessageID": &types.AttributeValueMemberS{Value: "exampleMessageID"},
+						},
 					}, nil
 				})
 			},
 			input: ListInput{
 				Type:  "inbox",
 				Year:  "2022",
 				Month: "03",
+				Order: "desc",
+				NextCursor: &Cursor{
+					QueryInfo: QueryInfo{
+						Type:  "inbox",
+						Year:  "2022",
+						Month: "03",
+						Order: "desc",
+					},
+				},
 			},
 			expected: &ListResult{
 				Count: 1,
@@ -54,7 +67,11 @@ func TestList(t *testing.T) {
 						Month: "03",
 						Order: "desc",
 					},
+					LastEvaluatedKey: map[string]types.AttributeValue{
+						"MessageID": &types.AttributeValueMemberS{Value: "exampleMessageID"},
+					},
 				},
+				HasMore: true,
 			},
 		},
 		{
@@ -68,6 +85,9 @@ func TestList(t *testing.T) {
 								"DateTime":      &types.AttributeValueMemberS{Value: "12-01:01:01"},
 							},
 						},
+						LastEvaluatedKey: map[string]types.AttributeValue{
+							"MessageID": &types.AttributeValueMemberS{Value: "exampleMessageID"},
+						},
 					}, nil
 				})
 			},
@@ -91,7 +111,11 @@ func TestList(t *testing.T) {
 						Month: "03",
 						Order: "desc",
 					},
+					LastEvaluatedKey: map[string]types.AttributeValue{
+						"MessageID": &types.AttributeValueMemberS{Value: "exampleMessageID"},
+					},
 				},
+				HasMore: true,
 			},
 		},
 		{
@@ -106,43 +130,48 @@ func TestList(t *testing.T) {
 			},
 			expectedErr: ErrInvalidInput,
 		},
-		// {
-		// 	client: func(t *testing.T) QueryAPI {
-		// 		return mockQueryAPI(func(ctx context.Context, params *dynamodb.QueryInput, optFns ...func(*dynamodb.Options)) (*dynamodb.QueryOutput, error) {
-		// 			assert.Fail(t, "this shouldn't be reached")
-		// 			return &dynamodb.QueryOutput{}, nil
-		// 		})
-		// 	},
-		// 	input: ListInput{
-		// 		Type: "sent",
-		// 		Year: "0",
-		// 	},
-		// 	expectedErr: ErrInvalidInput,
-		// },
-		// {
-		// 	client: func(t *testing.T) QueryAPI {
-		// 		return mockQueryAPI(func(ctx context.Context, params *dynamodb.QueryInput, optFns ...func(*dynamodb.Options)) (*dynamodb.QueryOutput, error) {
-		// 			return &dynamodb.QueryOutput{}, errors.New("error")
-		// 		})
-		// 	},
-		// 	input: ListInput{
-		// 		Type:  "draft",
-		// 		Year:  "2022",
-		// 		Month: "3",
-		// 	},
-		// 	expectedErr: errors.New("error"),
-		// },
-		// {
-		// 	input: ListInput{
-		// 		Type: "draft",
-		// 		NextCursor: &Cursor{
-		// 			QueryInfo: QueryInfo{
-		// 				Type: "inbox",
-		// 			},
-		// 		},
-		// 	},
-		// 	expectedErr: ErrQueryNotMatch,
-		// },
+		{
+			client: func(t *testing.T) QueryAPI {
+				return mockQueryAPI(func(ctx context.Context, params *dynamodb.QueryInput, optFns ...func(*dynamodb.Options)) (*dynamodb.QueryOutput, error) {
+					assert.Fail(t, "this shouldn't be reached")
+					return &dynamodb.QueryOutput{}, nil
+				})
+			},
+			input: ListInput{
+				Type: "sent",
+				Year: "0",
+			},
+			expectedErr: ErrInvalidInput,
+		},
+		{
+			client: func(t *testing.T) QueryAPI {
+				return mockQueryAPI(func(ctx context.Context, params *dynamodb.QueryInput, optFns ...func(*dynamodb.Options)) (*dynamodb.QueryOutput, error) {
+					return &dynamodb.QueryOutput{}, errors.New("error")
+				})
+			},
+			input: ListInput{
+				Type:  "draft",
+				Year:  "2022",
+				Month: "3",
+			},
+			expectedErr: errors.New("error"),
+		},
+		{
+			client: func(t *testing.T) QueryAPI {
+				return mockQueryAPI(func(ctx context.Context, params *dynamodb.QueryInput, optFns ...func(*dynamodb.Options)) (*dynamodb.QueryOutput, error) {
+					return &dynamodb.QueryOutput{}, nil
+				})
+			},
+			input: ListInput{
+				Type: "draft",
+				NextCursor: &Cursor{
+					QueryInfo: QueryInfo{
+						Type: "inbox",
+					},
+				},
+			},
+			expectedErr: ErrQueryNotMatch,
+		},
 	}
 
 	for i, test := range tests {