GODRIVER-1410 Add retryReads URI option (#228)

Author: Divjot Arora

mongo/client_test.go

@@ -179,18 +179,59 @@ func TestClient(t *testing.T) {
 		assert.Equal(t, rc, client.readConcern, "expected read concern %v, got %v", rc, client.readConcern)
 	})
 	t.Run("retry writes", func(t *testing.T) {
+		retryWritesURI := "mongodb://localhost:27017/?retryWrites=false"
+		retryWritesErrorURI := "mongodb://localhost:27017/?retryWrites=foobar"
+
 		testCases := []struct {
 			name          string
 			opts          *options.ClientOptions
+			expectErr     bool
 			expectedRetry bool
 		}{
-			{"default", options.Client(), true},
-			{"custom", options.Client().SetRetryWrites(false), false},
+			{"default", options.Client(), false, true},
+			{"custom options", options.Client().SetRetryWrites(false), false, false},
+			{"custom URI", options.Client().ApplyURI(retryWritesURI), false, false},
+			{"custom URI error", options.Client().ApplyURI(retryWritesErrorURI), true, false},
 		}
 		for _, tc := range testCases {
-			client := setupClient(tc.opts)
-			assert.Equal(t, tc.expectedRetry, client.retryWrites,
-				"expected retryWrites %v, got %v", tc.expectedRetry, client.retryWrites)
+			t.Run(tc.name, func(t *testing.T) {
+				client, err := NewClient(tc.opts)
+				if tc.expectErr {
+					assert.NotNil(t, err, "expected error, got nil")
+					return
+				}
+				assert.Nil(t, err, "configuration error: %v", err)
+				assert.Equal(t, tc.expectedRetry, client.retryWrites, "expected retryWrites %v, got %v",
+					tc.expectedRetry, client.retryWrites)
+			})
+		}
+	})
+	t.Run("retry reads", func(t *testing.T) {
+		retryReadsURI := "mongodb://localhost:27017/?retryReads=false"
+		retryReadsErrorURI := "mongodb://localhost:27017/?retryReads=foobar"
+
+		testCases := []struct {
+			name          string
+			opts          *options.ClientOptions
+			expectErr     bool
+			expectedRetry bool
+		}{
+			{"default", options.Client(), false, true},
+			{"custom options", options.Client().SetRetryReads(false), false, false},
+			{"custom URI", options.Client().ApplyURI(retryReadsURI), false, false},
+			{"custom URI error", options.Client().ApplyURI(retryReadsErrorURI), true, false},
+		}
+		for _, tc := range testCases {
+			t.Run(tc.name, func(t *testing.T) {
+				client, err := NewClient(tc.opts)
+				if tc.expectErr {
+					assert.NotNil(t, err, "expected error, got nil")
+					return
+				}
+				assert.Nil(t, err, "configuration error: %v", err)
+				assert.Equal(t, tc.expectedRetry, client.retryReads, "expected retryReads %v, got %v",
+					tc.expectedRetry, client.retryReads)
+			})
 		}
 	})
 	t.Run("write concern", func(t *testing.T) {

mongo/options/clientoptions.go

@@ -219,6 +219,10 @@ func (c *ClientOptions) ApplyURI(uri string) *ClientOptions {
 		c.RetryWrites = &cs.RetryWrites
 	}
 
+	if cs.RetryReadsSet {
+		c.RetryReads = &cs.RetryReads
+	}
+
 	if cs.ReplicaSet != "" {
 		c.ReplicaSet = &cs.ReplicaSet
 	}

x/mongo/driver/connstring/connstring.go

@@ -64,6 +64,8 @@ type ConnString struct {
 	ReadPreferenceTagSets              []map[string]string
 	RetryWrites                        bool
 	RetryWritesSet                     bool
+	RetryReads                         bool
+	RetryReadsSet                      bool
 	MaxStaleness                       time.Duration
 	MaxStalenessSet                    bool
 	ReplicaSet                         string
@@ -553,6 +555,17 @@ func (p *parser) addOption(pair string) error {
 		}
 
 		p.RetryWritesSet = true
+	case "retryreads":
+		switch value {
+		case "true":
+			p.RetryReads = true
+		case "false":
+			p.RetryReads = false
+		default:
+			return fmt.Errorf("invalid value for %s: %s", key, value)
+		}
+
+		p.RetryReadsSet = true
 	case "serverselectiontimeoutms":
 		n, err := strconv.Atoi(value)
 		if err != nil || n < 0 {

x/mongo/driver/connstring/connstring_test.go

@@ -389,6 +389,7 @@ func TestRetryWrites(t *testing.T) {
 	}{
 		{s: "retryWrites=true", expected: true},
 		{s: "retryWrites=false", expected: false},
+		{s: "retryWrites=foobar", expected: false, err: true},
 	}
 
 	for _, test := range tests {
@@ -397,11 +398,37 @@ func TestRetryWrites(t *testing.T) {
 			cs, err := connstring.Parse(s)
 			if test.err {
 				require.Error(t, err)
-			} else {
-				require.NoError(t, err)
-				require.Equal(t, test.expected, cs.RetryWrites)
-				require.Equal(t, true, cs.RetryWritesSet)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, test.expected, cs.RetryWrites)
+			require.True(t, cs.RetryWritesSet)
+		})
+	}
+}
+
+func TestRetryReads(t *testing.T) {
+	tests := []struct {
+		s        string
+		expected bool
+		err      bool
+	}{
+		{s: "retryReads=true", expected: true},
+		{s: "retryReads=false", expected: false},
+		{s: "retryReads=foobar", expected: false, err: true},
+	}
+
+	for _, test := range tests {
+		s := fmt.Sprintf("mongodb://localhost/?%s", test.s)
+		t.Run(s, func(t *testing.T) {
+			cs, err := connstring.Parse(s)
+			if test.err {
+				require.Error(t, err)
+				return
 			}
+			require.NoError(t, err)
+			require.Equal(t, test.expected, cs.RetryReads)
+			require.True(t, cs.RetryReadsSet)
 		})
 	}
 }