Allow map keys with brackets

fixed #44

formam.go

@@ -210,65 +210,71 @@ func (dec Decoder) init() error {
 // analyzePath analyzes the current path to walk through it.
 // For example: users[0].name
 func (dec *Decoder) analyzePath() (err error) {
-	inBracket := false
-	bracketClosed := false
+	traversedByBracket := false
+	nesting := 0
 	lastPos := 0
-	endPos := 0
 
 	// parse path
 	for i, char := range []byte(dec.path) {
-		if char == '[' && inBracket == false {
-			// found an opening bracket
-			bracketClosed = false
-			inBracket = true
-			dec.field = dec.path[lastPos:i]
-			lastPos = i + 1
-			continue
-		} else if inBracket {
-			// it is inside of bracket, so get its value
-			if char == ']' {
-				// found an closing bracket, so it will be recently close, so put as true the bracketClosed
-				// and put as false inBracket and pass the value of bracket to dec.key
-				inBracket = false
-				bracketClosed = true
-				if endPos == 0 { // foo[] without number.
-					dec.index = dec.path[lastPos:i]
-				} else {
-					dec.index = dec.path[lastPos:endPos]
-				}
-				lastPos = i + 1
-				// traverse the path
-				err = dec.traverse()
-				// flush the index already used by traverse
-				dec.index = ""
-				// check if the "traverse" failed
-				if err != nil {
-					return
-				}
-			} else {
-				// still inside the bracket, so to save the end position
-				endPos = i + 1
-			}
-			continue
-		} else if !inBracket {
-			// not found any bracket, so try found a field
-			if char == '.' {
-				// found a field, we need to know if the field is next of a closing bracket,
-				// for example: [0].Field
-				if bracketClosed {
-					bracketClosed = false
-					lastPos = i + 1
-					continue
-				}
-				// found a field, but is not next of a closing bracket, for example: Field1.Field2
+		switch char {
+		case '[':
+			// save current access field
+			if nesting == 0 {
+				traversedByBracket = false
 				dec.field = dec.path[lastPos:i]
-				//dec.field = tmp[:i]
 				lastPos = i + 1
-				if err = dec.traverse(); err != nil {
-					return
-				}
 			}
-			continue
+			nesting += 1
+
+		case ']':
+			// no matching open bracket - regular character
+			if nesting == 0 {
+				continue
+			}
+
+			// decrease nesting
+			nesting -= 1
+			// if still inside outer brackets - regular character
+			// for example: [nested[brackets]]
+			if nesting > 0 {
+				continue
+			}
+
+			traversedByBracket = true
+			dec.index = dec.path[lastPos:i]
+			lastPos = i + 1
+			// traverse the path
+			err = dec.traverse()
+			// flush the index already used by traverse
+			dec.index = ""
+			// check if the "traverse" failed
+			if err != nil {
+				return
+			}
+
+		case '.':
+			// inside brackets - regular character
+			// for example: [key.with.dots]
+			if nesting > 0 {
+				continue
+			}
+
+			// found a field, we need to know if the field is next to a closing bracket,
+			// if it is then no need to traverse again
+			// for example: [0].Field
+			if traversedByBracket {
+				traversedByBracket = false
+				lastPos = i + 1
+				continue
+			}
+
+			// found a field, but is not next to a closing bracket,
+			// for example: Field1.Field2
+			dec.field = dec.path[lastPos:i]
+			lastPos = i + 1
+			if err = dec.traverse(); err != nil {
+				return
+			}
 		}
 	}
 

formam_test.go

@@ -1026,3 +1026,52 @@ func errorContains(out error, want string) bool {
 	}
 	return strings.Contains(out.Error(), want)
 }
+
+func TestBracketsAndNestedPointers(t *testing.T) {
+	var s struct {
+		MapStringString    map[string]string
+		MapStringPtrStruct map[string]struct {
+			ID string
+		}
+		MapStringMapStringString map[string]map[string]string
+	}
+
+	vals := url.Values{
+		"MapStringString[a[b][c]d]":             []string{"MapStringString[a[b][c]d]"},
+		"MapStringString[name.with.dots]":       []string{"MapStringString[name.with.dots]"},
+		"MapStringPtrStruct[k2]ID":              []string{"MapStringPtrStruct[k2]ID"},
+		"MapStringMapStringString[a[b[c]d]]q]w": []string{"MapStringMapStringString[a[b[c]d]]q]w"},
+	}
+
+	dec := formam.NewDecoder(nil)
+
+	if err := dec.Decode(vals, &s); err != nil {
+		t.Fatalf("error when decode %s", err)
+	}
+
+	if v, ok := s.MapStringString["a[b][c]d"]; !ok {
+		t.Error("The key \"a[b][c]d\" in MapStringString does not exists")
+	} else if v != "MapStringString[a[b][c]d]" {
+		t.Error("The value in key \"a[b][c]d\" of MapStringString is incorrect")
+	}
+
+	if v, ok := s.MapStringString["name.with.dots"]; !ok {
+		t.Error("The key \"name.with.dots\" in MapStringString does not exists")
+	} else if v != "MapStringString[name.with.dots]" {
+		t.Error("The value in key \"name.with.dots\" of MapStringString is incorrect")
+	}
+
+	if v, ok := s.MapStringPtrStruct["k2"]; !ok {
+		t.Error("The key \"k2\" in MapStringPtrStruct does not exists")
+	} else if v.ID != "MapStringPtrStruct[k2]ID" {
+		t.Error("The value in key \"k2\" of MapStringPtrStruct is incorrect")
+	}
+
+	if v, ok := s.MapStringMapStringString["a[b[c]d]"]; !ok {
+		t.Error("The key \"a[b[c]d]\" in MapStringMapStringString does not exists")
+	} else if vv, ok := v["q]w"]; !ok {
+		t.Error("The key \"q]w\" in MapStringMapStringString[a[b[c]d]] does not exists")
+	} else if vv != "MapStringMapStringString[a[b[c]d]]q]w" {
+		t.Error("The value in key \"q]w\" of MapStringMapStringString[a[b[c]d]] is incorrect")
+	}
+}