add QueryMatcher interface for customizing SQL matching

options.go

@@ -10,3 +10,13 @@ func ValueConverterOption(converter driver.ValueConverter) func(*sqlmock) error
 		return nil
 	}
 }
+
+// QueryMatcherOption allows to customize SQL query matcher
+// and match SQL query strings in more sophisticated ways.
+// The default QueryMatcher is QueryMatcherRegexp.
+func QueryMatcherOption(queryMatcher QueryMatcher) func(*sqlmock) error {
+	return func(s *sqlmock) error {
+		s.queryMatcher = queryMatcher
+		return nil
+	}
+}

query.go

@@ -0,0 +1,68 @@
+package sqlmock
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+var re = regexp.MustCompile("\\s+")
+
+// strip out new lines and trim spaces
+func stripQuery(q string) (s string) {
+	return strings.TrimSpace(re.ReplaceAllString(q, " "))
+}
+
+// QueryMatcher is an SQL query string matcher interface,
+// which can be used to customize validation of SQL query strings.
+// As an exaple, external library could be used to build
+// and validate SQL ast, columns selected.
+//
+// sqlmock can be customized to implement a different QueryMatcher
+// configured through an option when sqlmock.New or sqlmock.NewWithDSN
+// is called, default QueryMatcher is QueryMatcherRegexp.
+type QueryMatcher interface {
+
+	// Match expected SQL query string without whitespace to
+	// actual SQL.
+	Match(expectedSQL, actualSQL string) error
+}
+
+// QueryMatcherFunc type is an adapter to allow the use of
+// ordinary functions as QueryMatcher. If f is a function
+// with the appropriate signature, QueryMatcherFunc(f) is a
+// QueryMatcher that calls f.
+type QueryMatcherFunc func(expectedSQL, actualSQL string) error
+
+// Match implements the QueryMatcher
+func (f QueryMatcherFunc) Match(expectedSQL, actualSQL string) error {
+	return f(expectedSQL, actualSQL)
+}
+
+// QueryMatcherRegexp is the default SQL query matcher
+// used by sqlmock. It parses expectedSQL to a regular
+// expression and attempts to match actualSQL.
+var QueryMatcherRegexp QueryMatcher = QueryMatcherFunc(func(expectedSQL, actualSQL string) error {
+	expect := stripQuery(expectedSQL)
+	actual := stripQuery(actualSQL)
+	re, err := regexp.Compile(expect)
+	if err != nil {
+		return err
+	}
+	if !re.MatchString(actual) {
+		return fmt.Errorf(`could not match actual sql: "%s" with expected regexp "%s"`, actual, re.String())
+	}
+	return nil
+})
+
+// QueryMatcherEqual is the SQL query matcher
+// which simply tries a case sensitive match of
+// expected and actual SQL strings without whitespace.
+var QueryMatcherEqual QueryMatcher = QueryMatcherFunc(func(expectedSQL, actualSQL string) error {
+	expect := stripQuery(expectedSQL)
+	actual := stripQuery(actualSQL)
+	if actual != expect {
+		return fmt.Errorf(`actual sql: "%s" does not equal to expected "%s"`, actual, expect)
+	}
+	return nil
+})

query_test.go

@@ -0,0 +1,87 @@
+package sqlmock
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestQueryStringStripping(t *testing.T) {
+	assert := func(actual, expected string) {
+		if res := stripQuery(actual); res != expected {
+			t.Errorf("Expected '%s' to be '%s', but got '%s'", actual, expected, res)
+		}
+	}
+
+	assert(" SELECT 1", "SELECT 1")
+	assert("SELECT   1 FROM   d", "SELECT 1 FROM d")
+	assert(`
+    SELECT c
+    FROM D
+`, "SELECT c FROM D")
+	assert("UPDATE  (.+) SET  ", "UPDATE (.+) SET")
+}
+
+func TestQueryMatcherRegexp(t *testing.T) {
+	type testCase struct {
+		expected string
+		actual   string
+		err      error
+	}
+
+	cases := []testCase{
+		{"?\\l", "SEL", fmt.Errorf("error parsing regexp: missing argument to repetition operator: `?`")},
+		{"SELECT (.+) FROM users", "SELECT name, email FROM users WHERE id = ?", nil},
+		{"Select (.+) FROM users", "SELECT name, email FROM users WHERE id = ?", fmt.Errorf(`could not match actual sql: "SELECT name, email FROM users WHERE id = ?" with expected regexp "Select (.+) FROM users"`)},
+		{"SELECT (.+) FROM\nusers", "SELECT name, email\n FROM users\n WHERE id = ?", nil},
+	}
+
+	for i, c := range cases {
+		err := QueryMatcherRegexp.Match(c.expected, c.actual)
+		if err == nil && c.err != nil {
+			t.Errorf(`got no error, but expected "%v" at %d case`, c.err, i)
+			continue
+		}
+		if err != nil && c.err == nil {
+			t.Errorf(`got unexpected error "%v" at %d case`, err, i)
+			continue
+		}
+		if err == nil {
+			continue
+		}
+		if err.Error() != c.err.Error() {
+			t.Errorf(`expected error "%v", but got "%v" at %d case`, c.err, err, i)
+		}
+	}
+}
+
+func TestQueryMatcherEqual(t *testing.T) {
+	type testCase struct {
+		expected string
+		actual   string
+		err      error
+	}
+
+	cases := []testCase{
+		{"SELECT name, email FROM users WHERE id = ?", "SELECT name, email\n FROM users\n WHERE id = ?", nil},
+		{"SELECT", "Select", fmt.Errorf(`actual sql: "Select" does not equal to expected "SELECT"`)},
+		{"SELECT from users", "SELECT from table", fmt.Errorf(`actual sql: "SELECT from table" does not equal to expected "SELECT from users"`)},
+	}
+
+	for i, c := range cases {
+		err := QueryMatcherEqual.Match(c.expected, c.actual)
+		if err == nil && c.err != nil {
+			t.Errorf(`got no error, but expected "%v" at %d case`, c.err, i)
+			continue
+		}
+		if err != nil && c.err == nil {
+			t.Errorf(`got unexpected error "%v" at %d case`, err, i)
+			continue
+		}
+		if err == nil {
+			continue
+		}
+		if err.Error() != c.err.Error() {
+			t.Errorf(`expected error "%v", but got "%v" at %d case`, c.err, err, i)
+		}
+	}
+}

sqlmock.go

@@ -81,11 +81,12 @@ type Sqlmock interface {
 }
 
 type sqlmock struct {
-	ordered   bool
-	dsn       string
-	opened    int
-	drv       *mockDriver
-	converter driver.ValueConverter
+	ordered      bool
+	dsn          string
+	opened       int
+	drv          *mockDriver
+	converter    driver.ValueConverter
+	queryMatcher QueryMatcher
 
 	expected []expectation
 }
@@ -104,6 +105,9 @@ func (c *sqlmock) open(options []func(*sqlmock) error) (*sql.DB, Sqlmock, error)
 	if c.converter == nil {
 		c.converter = driver.DefaultParameterConverter
 	}
+	if c.queryMatcher == nil {
+		c.queryMatcher = QueryMatcherRegexp
+	}
 	return db, c, db.Ping()
 }
 

util.go

@@ -1,13 +0,0 @@
-package sqlmock
-
-import (
-	"regexp"
-	"strings"
-)
-
-var re = regexp.MustCompile("\\s+")
-
-// strip out new lines and trim spaces
-func stripQuery(q string) (s string) {
-	return strings.TrimSpace(re.ReplaceAllString(q, " "))
-}

util_test.go

@@ -1,21 +0,0 @@
-package sqlmock
-
-import (
-	"testing"
-)
-
-func TestQueryStringStripping(t *testing.T) {
-	assert := func(actual, expected string) {
-		if res := stripQuery(actual); res != expected {
-			t.Errorf("Expected '%s' to be '%s', but got '%s'", actual, expected, res)
-		}
-	}
-
-	assert(" SELECT 1", "SELECT 1")
-	assert("SELECT   1 FROM   d", "SELECT 1 FROM d")
-	assert(`
-    SELECT c
-    FROM D
-`, "SELECT c FROM D")
-	assert("UPDATE  (.+) SET  ", "UPDATE (.+) SET")
-}