properly anchor regexp patterns to end of term

added integration tests for regexp anchoring
fixes #329

query_regexp.go

@@ -11,6 +11,7 @@ package bleve
 
 import (
 	"regexp"
+	"strings"
 
 	"github.com/blevesearch/bleve/index"
 	"github.com/blevesearch/bleve/search"
@@ -58,8 +59,16 @@ func (q *regexpQuery) Searcher(i index.IndexReader, m *IndexMapping, explain boo
 		field = m.DefaultField
 	}
 	if q.compiled == nil {
+		// require that pattern be anchored to start and end of term
+		actualRegexp := q.Regexp
+		if !strings.HasPrefix(actualRegexp, "^") {
+			actualRegexp = "^" + actualRegexp
+		}
+		if !strings.HasSuffix(actualRegexp, "$") {
+			actualRegexp = actualRegexp + "$"
+		}
 		var err error
-		q.compiled, err = regexp.Compile(q.Regexp)
+		q.compiled, err = regexp.Compile(actualRegexp)
 		if err != nil {
 			return nil, err
 		}

test/tests/basic/searches.json

@@ -582,5 +582,39 @@
 				}
 			]
 		}
+	},
+	{
+		"comment": "test regexp matching term",
+		"search": {
+			"from": 0,
+			"size": 10,
+			"query": {
+				"field": "name",
+				"regexp": "mar.*"
+			}
+		},
+		"result": {
+			"total_hits": 1,
+			"hits": [
+				{
+					"id": "a"
+				}
+			]
+		}
+	},
+	{
+		"comment": "test regexp that should not match when properly anchored",
+		"search": {
+			"from": 0,
+			"size": 10,
+			"query": {
+				"field": "name",
+				"regexp": "mar."
+			}
+		},
+		"result": {
+			"total_hits": 0,
+			"hits": []
+		}
 	}
 ]