Correctly initialize createMeasurement maps

Full unit tests added for happy paths.

internal_test.go

@@ -90,6 +90,78 @@ func TestMeasurement_expandExpr(t *testing.T) {
 	}
 }
 
+// Ensure the createMeasurementsIfNotExistsCommand operates correctly.
+func TestCreateMeasurementsCommand(t *testing.T) {
+	var err error
+	var n int
+	c := newCreateMeasurementsIfNotExistsCommand("foo")
+	if c == nil {
+		t.Fatal("createMeasurementsIfNotExistsCommand is nil")
+	}
+
+	// Add Measurement.
+	err = c.addMeasurementIfNotExists("bar")
+	if err != nil {
+		t.Fatal("error adding measurement bar")
+	}
+	err = c.addMeasurementIfNotExists("bar")
+	if err != nil {
+		t.Fatal("error re-adding measurement bar")
+	}
+
+	n = len(c.Measurements)
+	if n != 1 {
+		t.Fatalf("wrong number of measurements, expected 1, got %d", n)
+	}
+
+	// Add Series, no tags.
+	err = c.addSeriesIfNotExists("bar", nil)
+	if err != nil {
+		t.Fatal("error adding series with nil tags")
+	}
+
+	// Add Series, some tags.
+	tags := map[string]string{"host": "server01"}
+	err = c.addSeriesIfNotExists("bar", tags)
+	if err != nil {
+		t.Fatal("error adding series with non-nil tags")
+	}
+
+	// Add Series, same tags again.
+	err = c.addSeriesIfNotExists("bar", tags)
+	if err != nil {
+		t.Fatal("error re-adding series with non-nil tags")
+	}
+
+	n = len(c.Measurements["bar"].Tags)
+	if n != 2 {
+		t.Fatalf("measurement has wrong number of tags, expected 2, got %d", n)
+	}
+
+	// Add a fields.
+	err = c.addFieldIfNotExists("bar", "value", influxql.Number)
+	if err != nil {
+		t.Fatal("error adding field \"value\"")
+	}
+
+	// Add same field again.
+	err = c.addFieldIfNotExists("bar", "value", influxql.Number)
+	if err != nil {
+		t.Fatal("error re-adding field \"value\"")
+	}
+
+	// Add another field.
+	err = c.addFieldIfNotExists("bar", "value2", influxql.String)
+	if err != nil {
+		t.Fatal("error re-adding field \"value2\"")
+	}
+
+	n = len(c.Measurements["bar"].Fields)
+	if n != 2 {
+		t.Fatalf("wrong number of fields, expected 2, got %d", n)
+	}
+}
+
 // MustParseExpr parses an expression string and returns its AST representation.
 func MustParseExpr(s string) influxql.Expr {
 	expr, err := influxql.ParseExpr(s)

server.go

@@ -1596,12 +1596,23 @@ type createMeasurementsIfNotExistsCommand struct {
 	Measurements map[string]createMeasurementSubcommand `json:"measurements"`
 }
 
+func newCreateMeasurementsIfNotExistsCommand(database string) *createMeasurementsIfNotExistsCommand {
+	return &createMeasurementsIfNotExistsCommand{
+		Database:     database,
+		Measurements: make(map[string]createMeasurementSubcommand),
+	}
+}
+
 // addMeasurementIfNotExists adds the Measurement to the command, but only if not already present
 // in the command.
 func (c *createMeasurementsIfNotExistsCommand) addMeasurementIfNotExists(name string) error {
 	_, ok := c.Measurements[name]
 	if !ok {
-		c.Measurements[name] = createMeasurementSubcommand{Name: name}
+		c.Measurements[name] = createMeasurementSubcommand{
+			Name:   name,
+			Tags:   make(map[string]map[string]string),
+			Fields: make(map[string]influxql.DataType),
+		}
 	}
 	return nil
 }