wildcard: Fix wildcard match behavior to support wide range.

This helps in supporting all types of patterns in wildcard match.

gjson.go

@@ -663,7 +663,7 @@ read_key:
 	if parts[depth-1].wild {
 		// the path part contains a wildcard character. we must do a wildcard
 		// match to determine if it truly matches.
-		matched = wildcardMatch(f.key, parts[depth-1].key)
+		matched = wildcardMatch(parts[depth-1].key, f.key)
 	} else {
 		// just a straight up equality check
 		matched = parts[depth-1].key == f.key
@@ -1070,33 +1070,3 @@ func stringLessInsensitive(a, b string) bool {
 	}
 	return len(a) < len(b)
 }
-
-// wilcardMatch returns true if str matches pattern. This is a very
-// simple wildcard match where '*' matches on any number characters
-// and '?' matches on any one character.
-func wildcardMatch(str, pattern string) bool {
-	if pattern == "*" {
-		return true
-	}
-	return deepMatch(str, pattern)
-}
-func deepMatch(str, pattern string) bool {
-	for len(pattern) > 0 {
-		switch pattern[0] {
-		default:
-			if len(str) == 0 || str[0] != pattern[0] {
-				return false
-			}
-		case '?':
-			if len(str) == 0 {
-				return false
-			}
-		case '*':
-			return wildcardMatch(str, pattern[1:]) ||
-				(len(str) > 0 && wildcardMatch(str[1:], pattern))
-		}
-		str = str[1:]
-		pattern = pattern[1:]
-	}
-	return len(str) == 0 && len(pattern) == 0
-}

match.go

@@ -0,0 +1,90 @@
+package gjson
+
+import "unicode/utf8"
+
+// wildcardMatch -  finds whether the text matches/satisfies the pattern string.
+// supports  '*' and '?' wildcards in the pattern string.
+// unlike path.Match(), considers a path as a flat name space while matching the pattern.
+// The difference is illustrated in the example here https://play.golang.org/p/Ega9qgD4Qz .
+func wildcardMatch(pattern, name string) (matched bool) {
+Pattern:
+	for len(pattern) > 0 {
+		var star bool
+		var chunk string
+		star, chunk, pattern = scanChunk(pattern)
+		if star && chunk == "" {
+			// Trailing * matches rest of string.
+			return true
+		}
+		// Look for match at current position.
+		t, ok := matchChunk(chunk, name)
+		// if we're the last chunk, make sure we've exhausted the name
+		// otherwise we'll give a false result even if we could still match
+		// using the star
+		if ok && (len(t) == 0 || len(pattern) > 0) {
+			name = t
+			continue
+		}
+		if star {
+			// Look for match skipping i+1 bytes.
+			for i := 0; i < len(name); i++ {
+				t, ok := matchChunk(chunk, name[i+1:])
+				if ok {
+					// if we're the last chunk, make sure we exhausted the name
+					if len(pattern) == 0 && len(t) > 0 {
+						continue
+					}
+					name = t
+					continue Pattern
+				}
+			}
+		}
+		return false
+	}
+	return len(name) == 0
+}
+
+// scanChunk gets the next segment of pattern, which is a non-star string
+// possibly preceded by a star.
+func scanChunk(pattern string) (star bool, chunk, rest string) {
+	for len(pattern) > 0 && pattern[0] == '*' {
+		pattern = pattern[1:]
+		star = true
+	}
+	inrange := false
+	var i int
+Scan:
+	for i = 0; i < len(pattern); i++ {
+		switch pattern[i] {
+		case '*':
+			if !inrange {
+				break Scan
+			}
+		}
+	}
+	return star, pattern[0:i], pattern[i:]
+}
+
+// matchChunk checks whether chunk matches the beginning of s.
+// If so, it returns the remainder of s (after the match).
+// Chunk is all single-character operators: literals, char classes, and ?.
+func matchChunk(chunk, s string) (rest string, ok bool) {
+	for len(chunk) > 0 {
+		if len(s) == 0 {
+			return
+		}
+		switch chunk[0] {
+		case '?':
+			_, n := utf8.DecodeRuneInString(s)
+			s = s[n:]
+			chunk = chunk[1:]
+		default:
+			if chunk[0] != s[0] {
+				return
+			}
+			s = s[1:]
+			chunk = chunk[1:]
+		}
+	}
+	return s, true
+}

match_test.go

@@ -0,0 +1,311 @@
+package gjson
+
+import (
+	"testing"
+)
+
+// TestWildcardMatch - Tests validate the logic of wild card matching.
+// `WildcardMatch` supports '*' and '?' wildcards.
+// Sample usage: In resource matching for folder policy validation.
+func TestWildcardMatch(t *testing.T) {
+	testCases := []struct {
+		pattern string
+		text    string
+		matched bool
+	}{
+		// Test case - 1.
+		// Test case with pattern containing key name with a prefix. Should accept the same text without a "*".
+		{
+			pattern: "my-folder/oo*",
+			text:    "my-folder/oo",
+			matched: true,
+		},
+		// Test case - 2.
+		// Test case with "*" at the end of the pattern.
+		{
+			pattern: "my-folder/In*",
+			text:    "my-folder/India/Karnataka/",
+			matched: true,
+		},
+		// Test case - 3.
+		// Test case with prefixes shuffled.
+		// This should fail.
+		{
+			pattern: "my-folder/In*",
+			text:    "my-folder/Karnataka/India/",
+			matched: false,
+		},
+		// Test case - 4.
+		// Test case with text expanded to the wildcards in the pattern.
+		{
+			pattern: "my-folder/In*/Ka*/Ban",
+			text:    "my-folder/India/Karnataka/Ban",
+			matched: true,
+		},
+		// Test case - 5.
+		// Test case with the  keyname part is repeated as prefix several times.
+		// This is valid.
+		{
+			pattern: "my-folder/In*/Ka*/Ban",
+			text:    "my-folder/India/Karnataka/Ban/Ban/Ban/Ban/Ban",
+			matched: true,
+		},
+		// Test case - 6.
+		// Test case to validate that `*` can be expanded into multiple prefixes.
+		{
+			pattern: "my-folder/In*/Ka*/Ban",
+			text:    "my-folder/India/Karnataka/Area1/Area2/Area3/Ban",
+			matched: true,
+		},
+		// Test case - 7.
+		// Test case to validate that `*` can be expanded into multiple prefixes.
+		{
+			pattern: "my-folder/In*/Ka*/Ban",
+			text:    "my-folder/India/State1/State2/Karnataka/Area1/Area2/Area3/Ban",
+			matched: true,
+		},
+		// Test case - 8.
+		// Test case where the keyname part of the pattern is expanded in the text.
+		{
+			pattern: "my-folder/In*/Ka*/Ban",
+			text:    "my-folder/India/Karnataka/Bangalore",
+			matched: false,
+		},
+		// Test case - 9.
+		// Test case with prefixes and wildcard expanded for all "*".
+		{
+			pattern: "my-folder/In*/Ka*/Ban*",
+			text:    "my-folder/India/Karnataka/Bangalore",
+			matched: true,
+		},
+		// Test case - 10.
+		// Test case with keyname part being a wildcard in the pattern.
+		{pattern: "my-folder/*",
+			text:    "my-folder/India",
+			matched: true,
+		},
+		// Test case - 11.
+		{
+			pattern: "my-folder/oo*",
+			text:    "my-folder/odo",
+			matched: false,
+		},
+
+		// Test case with pattern containing wildcard '?'.
+		// Test case - 12.
+		// "my-folder?/" matches "my-folder1/", "my-folder2/", "my-folder3" etc...
+		// doesn't match "myfolder/".
+		{
+			pattern: "my-folder?/abc*",
+			text:    "myfolder/abc",
+			matched: false,
+		},
+		// Test case - 13.
+		{
+			pattern: "my-folder?/abc*",
+			text:    "my-folder1/abc",
+			matched: true,
+		},
+		// Test case - 14.
+		{
+			pattern: "my-?-folder/abc*",
+			text:    "my--folder/abc",
+			matched: false,
+		},
+		// Test case - 15.
+		{
+			pattern: "my-?-folder/abc*",
+			text:    "my-1-folder/abc",
+			matched: true,
+		},
+		// Test case - 16.
+		{
+			pattern: "my-?-folder/abc*",
+			text:    "my-k-folder/abc",
+			matched: true,
+		},
+		// Test case - 17.
+		{
+			pattern: "my??folder/abc*",
+			text:    "myfolder/abc",
+			matched: false,
+		},
+		// Test case - 18.
+		{
+			pattern: "my??folder/abc*",
+			text:    "my4afolder/abc",
+			matched: true,
+		},
+		// Test case - 19.
+		{
+			pattern: "my-folder?abc*",
+			text:    "my-folder/abc",
+			matched: true,
+		},
+		// Test case 20-21.
+		// '?' matches '/' too. (works with s3).
+		// This is because the namespace is considered flat.
+		// "abc?efg" matches both "abcdefg" and "abc/efg".
+		{
+			pattern: "my-folder/abc?efg",
+			text:    "my-folder/abcdefg",
+			matched: true,
+		},
+		{
+			pattern: "my-folder/abc?efg",
+			text:    "my-folder/abc/efg",
+			matched: true,
+		},
+		// Test case - 22.
+		{
+			pattern: "my-folder/abc????",
+			text:    "my-folder/abc",
+			matched: false,
+		},
+		// Test case - 23.
+		{
+			pattern: "my-folder/abc????",
+			text:    "my-folder/abcde",
+			matched: false,
+		},
+		// Test case - 24.
+		{
+			pattern: "my-folder/abc????",
+			text:    "my-folder/abcdefg",
+			matched: true,
+		},
+		// Test case 25-26.
+		// test case with no '*'.
+		{
+			pattern: "my-folder/abc?",
+			text:    "my-folder/abc",
+			matched: false,
+		},
+		{
+			pattern: "my-folder/abc?",
+			text:    "my-folder/abcd",
+			matched: true,
+		},
+		{
+			pattern: "my-folder/abc?",
+			text:    "my-folder/abcde",
+			matched: false,
+		},
+		// Test case 27.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnop",
+			matched: false,
+		},
+		// Test case 28.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnopqrst/mnopqr",
+			matched: true,
+		},
+		// Test case 29.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnopqrst/mnopqrs",
+			matched: true,
+		},
+		// Test case 30.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnop",
+			matched: false,
+		},
+		// Test case 31.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnopq",
+			matched: true,
+		},
+		// Test case 32.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnopqr",
+			matched: true,
+		},
+		// Test case 33.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopqand",
+			matched: true,
+		},
+		// Test case 34.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopand",
+			matched: false,
+		},
+		// Test case 35.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopqand",
+			matched: true,
+		},
+		// Test case 36.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mn",
+			matched: false,
+		},
+		// Test case 37.
+		{
+			pattern: "my-folder/mnop*?",
+			text:    "my-folder/mnopqrst/mnopqrs",
+			matched: true,
+		},
+		// Test case 38.
+		{
+			pattern: "my-folder/mnop*??",
+			text:    "my-folder/mnopqrst",
+			matched: true,
+		},
+		// Test case 39.
+		{
+			pattern: "my-folder/mnop*qrst",
+			text:    "my-folder/mnopabcdegqrst",
+			matched: true,
+		},
+		// Test case 40.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopqand",
+			matched: true,
+		},
+		// Test case 41.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopand",
+			matched: false,
+		},
+		// Test case 42.
+		{
+			pattern: "my-folder/mnop*?and?",
+			text:    "my-folder/mnopqanda",
+			matched: true,
+		},
+		// Test case 43.
+		{
+			pattern: "my-folder/mnop*?and",
+			text:    "my-folder/mnopqanda",
+			matched: false,
+		},
+		// Test case 44.
+
+		{
+			pattern: "my-?-folder/abc*",
+			text:    "my-folder/mnopqanda",
+			matched: false,
+		},
+	}
+	// Iterating over the test cases, call the function under test and asert the output.
+	for i, testCase := range testCases {
+		actualResult := wildcardMatch(testCase.pattern, testCase.text)
+		if testCase.matched != actualResult {
+			t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.matched, actualResult)
+		}
+	}
+}