Refactor regex part of macros

Author: fridgepoet

macros.go

@@ -141,11 +141,10 @@ func interpolate(driver Driver, query *Query) (string, error) {
 	}
 	rawSQL := query.RawSQL
 	for key, macro := range macros {
-		rgx, err := regexp.Compile(getMacroRegex(key))
+		matches, err := getMatches(key, rawSQL)
 		if err != nil {
 			return rawSQL, err
 		}
-		matches := rgx.FindAllStringSubmatch(rawSQL, -1)
 		for _, match := range matches {
 			if len(match) == 0 {
 				// There were no matches for this macro
@@ -170,3 +169,11 @@ func interpolate(driver Driver, query *Query) (string, error) {
 
 	return rawSQL, nil
 }
+
+func getMatches(macroName, rawSQL string) ([][]string, error) {
+	rgx, err := regexp.Compile(getMacroRegex(macroName))
+	if err != nil {
+		return nil, err
+	}
+	return rgx.FindAllStringSubmatch(rawSQL, -1), nil
+}

macros_test.go

@@ -79,3 +79,28 @@ func TestInterpolate(t *testing.T) {
 		})
 	}
 }
+
+func TestGetMacroRegex(t *testing.T) {
+	t.Run("returns composed regular expression", func(t *testing.T) {
+		assert.Equal(t, `\$__some_string\b(?:\((.*?)\))?`, getMacroRegex("some_string"))
+	})
+	t.Run("FindAllStringSubmatch returns DefaultMacros", func(t *testing.T) {
+		for macroName := range DefaultMacros {
+			matches, err := getMatches(macroName, fmt.Sprintf("$__%s", macroName))
+
+			assert.NoError(t, err)
+			assert.Equal(t, [][]string{{fmt.Sprintf("$__%s", macroName), ""}}, matches)
+		}
+	})
+}
+
+func TestGetMacroRegex_returns_composed_regular_expression(t *testing.T) {
+	assert.Equal(t, `\$__some_string\b(?:\((.*?)\))?`, getMacroRegex("some_string"))
+}
+
+func TestGetMatches_does_not_match_for_macro_name_which_is_substring(t *testing.T) {
+	matches, err := getMatches("timeFilter", "$__timeFilterEpoch(time_column)")
+
+	assert.NoError(t, err)
+	assert.Nil(t, matches)
+}