JSP parser throws errors for certain scenarios

[CodesAway]

Found during work when using BEX to parse our JSP files. Below is the fix I found. I'll also add some unit tests

    public static ImmutableIntRangeMap<ParsingState> parseJSPTextStates(final CharSequence text) {
        // TODO: used Java as a basic and need to enhance
        // For example, to handle JSP Expression
        // https://www.tutorialspoint.com/jsp/jsp_syntax.htm

        // TODO: need to make RangeMap class and correctly and nested ranges
        // Currently, doesn't work as expected
        // "stuff <%= expression%> more stuff"
        // "More stuff" after the expression should be seen as part of the String literal,
        // but isn't since it gets the last range, which is the expression, which is over
        // Think can fix by end the state when go into a inner state
        // Then, when leave inner state, start a new state based on the outer state

        // TODO: make RangeMap class to handle this
        // When adding a new record, check for overlap using the below logic
        // + An overlap occurs if and only if
        // a) The added range's start in part of an existing range
        // * Can check by finding existing range in map and seeing if the added range's start is in the middle
        // * BEXUtilities.getEntryInRanges
        // b) An existing range's start is contained in the new range
        // * Can do a subRange check on the existing NavigableMap and see if there are any entries
        // If there's an overlap, handle by breaking apart ranges in pieces

        // Parse text to get states
        // * Block comment
        // * Line comment
        // * In String literal
        // * Other stuff?

        // Reference: https://www.tutorialspoint.com/jsp/jsp_syntax.htm

        ImmutableIntRangeMap.Builder<ParsingState> builder = ImmutableIntRangeMap.builder();
        ArrayDeque<ParsingState> stateStack = new ArrayDeque<>();
        ArrayDeque<Integer> startTextInfoStack = new ArrayDeque<>();
        ArrayDeque<Integer> parentStartStack = new ArrayDeque<>();

        boolean isJava = false;
        // HTML tag
        boolean isTag = false;
        // TODO: should I refactor and use this? how would I use it?
        //      String expectedEnd = "";

        for (int i = 0; i < text.length(); i++) {
            //          if (i == 50) {
            //              System.out.println("Debug");
            //          }

            char c = text.charAt(i);

            //          System.out.printf("Index %s%n"
            //                  + "Char %s%n"
            //                  + "States %s%n"
            //                  + "Start %s%n"
            //                  + "Parent %s%n", i, c, stateStack, startTextInfoStack, parentStartStack);

            ParsingState currentState = unwrapParsingState(stateStack.peek());

            //          if (currentState == null) {
            //              System.out.println("Parent: " + i);
            //          }

            if (currentState == IN_STRING_LITERAL) {
                if (c == '\\') {
                    // Escape next character
                    if (nextChar(text, i) == '\0') {
                        break;
                    }

                    i++;
                } else if (c == '"') {
                    popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
                } else if (isTag && hasText(text, i, "<%=")) {
                    pushNextLevelParsingState(IN_EXPRESSION_BLOCK, i, builder, stateStack, startTextInfoStack,
                            parentStartStack);
                    i += 2;

                    isJava = true;
                }

                // Other characters don't matter??
                // TODO: handle unicode and other escaping in String literal
            } else if (currentState == IN_SECONDARY_STRING_LITERAL) {
                if (c == '\\') {
                    // Escape next character
                    if (nextChar(text, i) == '\0') {
                        break;
                    }

                    i++;
                } else if (c == '\'') {
                    popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
                } else if (hasText(text, i, "<%=")) {
                    pushNextLevelParsingState(IN_EXPRESSION_BLOCK, i, builder, stateStack, startTextInfoStack,
                            parentStartStack);
                    i += 2;
                }

                // Other characters don't matter??
                // TODO: handle unicode and other escaping in String literal

                // TODO: Java comments only valid in <% code block %>
            } else if (isJava && hasText(text, i, "%>")) {
                isJava = false;

                //              System.out.println("Current: " + currentState
                //                      + "\t"
                //                      + i);

                if (currentState != IN_EXPRESSION_BLOCK) {
                    // End the current state on the prior character
                    popParsingState(i - 1, builder, stateStack, startTextInfoStack, parentStartStack);
                }

                i++;
                popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
            } else if (isJava && currentState == IN_LINE_COMMENT) {
                if (c == '\n' || c == '\r') {
                    popParsingState(i - 1, builder, stateStack, startTextInfoStack, parentStartStack);
                    i = handleLineTerminator(i, c, text, builder, stateStack, startTextInfoStack, parentStartStack);
                    //                  int startTextInfo = startTextInfoStack.pop();
                    //                  builder.put(IntBEXRange.of(startTextInfo, i), stateStack.pop());
                }
                // Other characters don't matter?
            } else if (isJava && currentState == IN_MULTILINE_COMMENT) {
                if (hasText(text, i, "*/")) {
                    i++;
                    popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
                    //                  int startTextInfo = startTextInfoStack.pop();
                    //                  builder.put(IntBEXRange.closed(startTextInfo, i), stateStack.pop());
                }
            } else if (currentState == IN_MULTILINE_COMMENT) {
                if (hasText(text, i, "--%>")) {
                    i += 3;
                    popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
                }
            } else if (currentState == IN_SECONDARY_MULTILINE_COMMENT) {
                if (hasText(text, i, "-->")) {
                    i += 2;
                    popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
                }
            } else if (isJava && c == '/' && nextChar(text, i) == '/') {
                pushNextLevelParsingState(IN_LINE_COMMENT, i, builder, stateStack, startTextInfoStack,
                        parentStartStack);
                i++;
            } else if (isJava && c == '/' && nextChar(text, i) == '*') {
                pushNextLevelParsingState(IN_MULTILINE_COMMENT, i, builder, stateStack, startTextInfoStack,
                        parentStartStack);
                i++;
            } else if (c == '"' && isTag) {
                pushNextLevelParsingState(IN_STRING_LITERAL, i, builder, stateStack, startTextInfoStack,
                        parentStartStack);
            } else if (c == '\'' && isTag) {
                pushNextLevelParsingState(IN_SECONDARY_STRING_LITERAL, i, builder, stateStack,
                        startTextInfoStack, parentStartStack);
            } else if (c == '"' && isJava) {
                pushParsingState(IN_STRING_LITERAL, i, stateStack, startTextInfoStack, parentStartStack);
            } else if (c == '\'' && isJava) {
                pushParsingState(IN_SECONDARY_STRING_LITERAL, i, stateStack, startTextInfoStack, parentStartStack);
            } else if (hasText(text, i, "<%--")) {
                pushParsingState(IN_MULTILINE_COMMENT, i, stateStack, startTextInfoStack, parentStartStack);
                i += 3;
            } else if (hasText(text, i, "<!--")) {
                pushParsingState(IN_SECONDARY_MULTILINE_COMMENT, i, stateStack, startTextInfoStack, parentStartStack);
                i += 3;
            } else if (hasText(text, i, "<%=")) {
                // In Java expression
                pushParsingState(IN_EXPRESSION_BLOCK, i, stateStack, startTextInfoStack, parentStartStack);
                i += 2;
                isJava = true;
            } else if (hasText(text, i, "<%!")) {
                pushParsingState(IN_EXPRESSION_BLOCK, i, stateStack, startTextInfoStack, parentStartStack);
                i += 2;
                isJava = true;
            } else if (hasText(text, i, "<%")) {
                // In Java scriptlet
                pushParsingState(IN_EXPRESSION_BLOCK, i, stateStack, startTextInfoStack, parentStartStack);
                i++;
                isJava = true;
            } else if (c == '<' && !isJava && !isTag) {
                pushParsingState(IN_TAG, i, stateStack, startTextInfoStack, parentStartStack);
                isTag = true;
            } else if (c == '>' && isTag && !isJava) {
                isTag = false;
                popParsingState(i, builder, stateStack, startTextInfoStack, parentStartStack);
            } else if (Character.isWhitespace(c)) {
                i = handleWhitespace(i, c, text, builder, stateStack, startTextInfoStack, parentStartStack);
            }
        }

        if (!stateStack.isEmpty()) {
            // TODO: what if there are multiple entries?
            // (this would suggest improperly formatted code)
            int startTextInfo = startTextInfoStack.pop();
            // TODO: does there need to be a parent?
            if (startTextInfo != text.length()) {
                builder.put(IntBEXRange.of(startTextInfo, text.length()), stateStack.pop());
            }
        }

        return builder.build();
    }

[CodesAway]

No unit tests were added, since I don't remember the scenario I changed thy code for... oops.

[CodesAway]

Nevermind, I already added unit tests and forgot, but noticed them when reviewing the changes for the pull merge. Yea!