代写CSCI 2134程序、代做Java编程设计、Java语言编程调试

日期：2021-03-04 10:54

CSCI 2134 Assignment 3

Due date: 11:59pm, Friday, March 19, 2021, submitted via Git

Objectives

Practice debugging code, using a symbolic debugger, and fixing errors.

Preparation:

Clone the Assignment 3 repository

https://git.cs.dal.ca/courses/2021-winter/csci-2134/assignment3/.git

where is your CSID.

Problem Statement

Take a piece of buggy code, debug it, and fix it.

Background

You have inherited some buggy code for computing shortest path solutions to the board game

Ticket to Ride. Your boss has fired the previous developer because they did not do any testing

and did not fix the bugs! She has hired you to debug and fix the code. She will provide you with

some unit tests (some of which fail), sample input and sample output of what should be produced.

Your job is to fix the bugs: Both the bugs exhibited by the unit tests and the ones by the

input. Good luck!

You will be provided with a full buggy codebase for JSON comparison, a specification, a set of unit

tests using JUnit5, sample input and expected output. Your job is to identify and fix all the bugs.

Given a game board of rail segments and a list of routes (pairs of cities), the code is supposed to

compute the total cost of building a network between the given routes, assuming that the shortest

distance for each route is chosen. This can be computed by computing shortest paths for each

route using Dijkstra’s shortest path algorithm.

You will be provided with a full buggy codebase for distance computation, a specification, a set

of unit tests using JUnit5, sample input and expected output. Your job is to identify and fix all

the bugs.

Task

1. Review the specification (specification.pdf) in the docs directory. You will absolutely

need to understand it and the code you are debugging. The main method for the program

is in RouteCost.java. Note that your boss finally got the buggy makeTree method in

City.java from the previous developer. Spend some time tracing through the code and creating

a diagram of how the classes and code are put together. This will help you a lot later on!

2. Fix all bugs that are identified by the tests generated by the unit tests in the following classes:

? City.java

? CityComparator.java

? Link.java

3. See buglist.txt file in the docs directory. One sample entry is included. For each bug

that you fix add an entry to this file that includes:

a. The file/class name where the bug was.

b. The method where the bug was

c. The line number(s) where the buggy code was

d. A description of what the bug was

e. A description of what the fix was.

4. The previous developer made a set of example input and expected output in the input_tests

directory. These tests will likely not pass yet even after fixing the bugs identified

by the unit tests.

? See the README.txt in this directory for help running the tests. The easiest method is to

copy your .java files from src to this directory and run the test.sh script in a terminal or git

bash command line shell.

? Compare the output in the .out files with the expected .gold files.

? For each output that differs from the expected output, debug the code and determine

the reason for the mismatch. Fix any identified bugs missed by the unit tests.

5. Record any new bugs found and fixed from Step 4 in the previously created buglist.txt

6. Commit and push back the bug fixes and the buglist.txt file to the remote repository.

Submission

All fixes and files must be committed and pushed back to the remote Git repository.

Grading

The following grading scheme will be used:

Task 4/4 3/4 2/4 1/4 0/4

Bugs found

[unit tests]

(20%)

4 to 5 bugs are

correctly identified

and documented.

Three (3) bugs

are correctly

identified and

documented.

Two (2) bugs

are correctly

identified and

documented.

One (1) bug is correctly

identified

and documented.

Zero (0) bugs

are correctly

identified and

documented.

Bugs fixed

[unit tests]

(20%)

4 to 5 bugs are

correctly fixed.

All unit tests

pass.

Three (3) bugs

are correctly

fixed.

Two (2) bugs

are correctly

fixed.

One (1) bug is correctly

fixed.

Zero (0) bugs

are correctly

fixed.

Bugs found

[input tests]

(20%)

2 to 3 bugs are

correctly identified

and documented.

N/A One (1) bug is

correctly identified

and documented.

N/A Zero (0) bugs

are correctly

identified and

documented.

Bugs fixed

[input tests]

(30%)

2 to 3 bugs are

correctly fixed.

All input tests

pass.

2 to 3 bugs are

correctly fixed.

One (1) bug is

correctly fixed.

Some input

tests pass

N/A Zero (0) bugs

are correctly

fixed.

Document

[buglist.txt]

Clarity

(10%)

Document

looks professional,

includes

all information,

and easy to

read

Document looks

ok. May be

hard to read or

missing some

information.

Document is

sloppy, inconsistent,

and has

missing information

Document is very

sloppy with significant

missing information

Document is

illegible or not

provided.

Hints

1. You will need to use a symbolic debugger to make headway. Using print-statements will be

possible but extremely painful.

2. You will need to step through the code to find the bugs.

3. There are about 2-3 bugs in the code (in addition to the ones identified by the unit tests). The

single bug report should cover all of them.