Merge pull request #7 from marekm4/list-keys

Add list operation

README.md

@@ -16,6 +16,11 @@ By default, it uses port `8080`, this can be changed by setting up `PORT` env. D
 See [websocket_test.go](websocket_test.go) for more examples.
 
 ### Queries
+#### List values
+```
+list user
+```
+
 #### Get value
 ```
 select username

database.go

@@ -2,6 +2,7 @@ package main
 
 import (
  "fmt"
+ "strings"
 )
 
 type Database struct {
@@ -14,6 +15,26 @@ func NewDatabase() Database {
  return Database{make(map[string]string), make(map[string]float64), make(map[string][]string)}
 }
 
+func (d Database) List(prefix string) []string {
+ keys := []string{}
+ for key := range d.Values {
+ if strings.HasPrefix(key, prefix) {
+ keys = append(keys, key)
+ }
+ }
+ for key := range d.Counters {
+ if strings.HasPrefix(key, prefix) {
+ keys = append(keys, key)
+ }
+ }
+ for key := range d.Lists {
+ if strings.HasPrefix(key, prefix) {
+ keys = append(keys, key)
+ }
+ }
+ return keys
+}
+
 func (d Database) Select(key string) []string {
  if value, ok := d.Values[key]; ok {
  return []string{value}

database_test.go

@@ -92,3 +92,18 @@ func TestDatabase_Clear(t *testing.T) {
  values := database.Select(key)
  assert.DeepEqual(t, values, []string{""})
 }
+
+func TestDatabase_List(t *testing.T) {
+ // Given database with user data
+ database := NewDatabase()
+ database.Update("user_name", "John")
+ database.Increment("user_money", 100.0)
+ database.Append("user_orders", "order 1")
+ database.Increment("account_money", 1000.0)
+
+ // When we get user keys
+ keys := database.List("user_")
+
+ // Then user keys are returned
+ assert.DeepEqual(t, keys, []string{"user_name", "user_money", "user_orders"})
+}

query.go

@@ -16,6 +16,14 @@ func (q EmptyQuery) Execute(_ Database) []string {
  return []string{}
 }
 
+type ListQuery struct {
+ Key string
+}
+
+func (q ListQuery) Execute(database Database) []string {
+ return database.List(q.Key)
+}
+
 type SelectQuery struct {
  Key string
 }
@@ -61,6 +69,9 @@ func ParseQuery(query string) Query {
  }
  operation := query[:i]
  key := query[i+1:]
+ if operation == "list" {
+ return ListQuery{key}
+ }
  if operation == "select" {
  return SelectQuery{key}
  }

query_test.go

@@ -10,7 +10,8 @@ func TestParseQuery(t *testing.T) {
  Query string
  Expected Query
  }{
- "Empty": {"select", EmptyQuery{}},
+ "Empty": {"list", EmptyQuery{}},
+ "List": {"list user", ListQuery{"user"}},
  "Select": {"select user_name", SelectQuery{"user_name"}},
  "Update": {"update user_name john", UpdateQuery{"user_name", "john"}},
  "Increment": {"increment user_money 5.5", IncrementQuery{"user_money", 5.5}},

websocket_test.go

@@ -30,6 +30,13 @@ func TestWebsocket(t *testing.T) {
  assert.NilError(t, err)
  assert.Equal(t, string(message), "john")
 
+ // Then value is on the list
+ err = ws.WriteMessage(websocket.TextMessage, []byte("list user"))
+ assert.NilError(t, err)
+ _, message, err = ws.ReadMessage()
+ assert.NilError(t, err)
+ assert.Equal(t, string(message), "username")
+
  // When we increment value
  err = ws.WriteMessage(websocket.TextMessage, []byte("increment money 100"))
  assert.NilError(t, err)