Return error message when improper types are used in SELECT

CHANGELOG.md

@@ -58,6 +58,7 @@
 - [#5865](https://github.com/influxdata/influxdb/issues/5865): Conversion to tsm fails with exceeds max index value
 - [#5924](https://github.com/influxdata/influxdb/issues/5924): Missing data after using influx\_tsm
 - [#5937](https://github.com/influxdata/influxdb/pull/5937): Rewrite SHOW SERIES to use query engine
+- [#5949](https://github.com/influxdata/influxdb/issues/5949): Return error message when improper types are used in SELECT
 
 ## v0.10.2 [2016-03-03]
 ### Bugfixes

influxql/select.go

@@ -372,7 +372,7 @@ func buildExprIterator(expr Expr, ic IteratorCreator, opt IteratorOptions) (Iter
 	case *ParenExpr:
 		return buildExprIterator(expr.Expr, ic, opt)
 	default:
-		panic(fmt.Sprintf("invalid expression type: %T", expr)) // FIXME
+		return nil, fmt.Errorf("invalid expression type: %T", expr)
 	}
 }
 

influxql/select_test.go

@@ -1686,3 +1686,32 @@ func TestSelect_UnsupportedCall(t *testing.T) {
 		t.Errorf("unexpected error: %s", err)
 	}
 }
+
+func TestSelect_InvalidQueries(t *testing.T) {
+	var ic IteratorCreator
+	ic.CreateIteratorFn = func(opt influxql.IteratorOptions) (influxql.Iterator, error) {
+		return &FloatIterator{}, nil
+	}
+
+	tests := []struct {
+		q   string
+		err string
+	}{
+		{
+			q:   `SELECT foobar(value) FROM cpu`,
+			err: `unsupported call: foobar`,
+		},
+		{
+			q:   `SELECT 'value' FROM cpu`,
+			err: `invalid expression type: *influxql.StringLiteral`,
+		},
+	}
+
+	for i, tt := range tests {
+		itrs, err := influxql.Select(MustParseSelectStatement(tt.q), &ic, nil)
+		if err == nil || err.Error() != tt.err {
+			t.Errorf("%d. expected error '%s', got '%s'", i, tt.err, err)
+		}
+		influxql.Iterators(itrs).Close()
+	}
+}