Test Cases

Start game without authentication returns 401

Start game with invalid mode returns 400

Submit move for wrong puzzle returns 400

Submit move with invalid format returns 400

Request hint when hints disabled returns 403

Request second hint returns 400

End session for non-existent game returns 404

End another user's game returns 403

Submit move for ended game returns 400

Start game when active session exists returns 409

Get puzzles with invalid rating range returns 400

Rate limiting prevents abuse

SQL injection attempt is blocked

XSS attempt in puzzle data is escaped

Large payload rejected

Expired JWT token returns 401

Concurrent move submissions handled

Network timeout handled gracefully

Server error returns 500 with safe message

Invalid theme ID in filter returns empty results

Calculation Mode is unrated

Default mode is Deep Think

Deep Think has no timer

Deep Think uses long sequences

Commitment Mode first move is untimed

Commitment Mode 3s timer after first move

Commitment Mode timer expiry fails puzzle

Checkmate Climb starts at mate-in-1

Checkmate Climb progresses to mate-in-2

Checkmate Climb resets to mate-in-1 on fail

Checkmate Climb max level

Hints allowed in Calculation Mode

Rating range slider clamps correctly

Deep Think score decay to zero at 300s

Score can go negative after zero-point time

Wrong attempt uses decayed score

Retry attempt yields zero score

Commitment mode zero-point at 100s

Coming Soon when mode not available

Commitment Mode timer is HIDDEN

Puzzle rating range selection works

Session-end shows session stats

Puzzle-end shows depth (moves played)

Commitment Mode tests pre-calculation

Mode selection changes start behavior

Puzzle Climb is rated (Glicko)

No time pressure (no clock)

Difficulty increases after consecutive solves

Difficulty decreases after consecutive failures

Mixed performance difficulty adjustment

Wrong move fails puzzle immediately

Rating gain on solve

Next puzzle loads after solve

Rating loss on fail

Next puzzle loads after fail (no game-over)

Hint reduces rating gain by 50%

Puzzle-end completion screen shown

Start without rating prompts initialization

Start without theme selection works

Level up after required solves (if level-based)

Level down after consecutive fails (if level-based)

Level does not drop below 1 (if level-based)

Highest level persists after dropping

Start game failure shows error

Coming Soon when mode not available

First puzzle starts near user's rating

Theme filtering works with single theme

Theme filtering works with multiple themes

Session-end shows game session stats

User can exit session anytime

Empty solution string is handled safely

Solution parsing ignores extra whitespace

Malformed UCI token is rejected

Invalid FEN is handled safely

Promotion piece mismatch is marked wrong

Underpromotion required is accepted

User cannot move during opponent turn

Move history controls stop at boundaries

Progress percent handles zero moves gracefully

Puzzle solution cache expires correctly

Game backup restores state within 1 hour

Game backup expires after 1 hour

Failed completion retried within 24 hours

Failed completion expires after 24 hours

Multi-tab backup conflict uses latest save

Negative or NaN time does not break scoring

Very short maxTimeSeconds does not break time bonus

Castling move validated correctly

En passant capture validated correctly

Alternate correct line is accepted

Puzzle Tempo puzzle-end shows rating earned

Puzzle Tempo puzzle-end shows rating loss

Puzzle Climb puzzle-end shows rating format

Calculation Mode puzzle-end shows depth

Session-end shows game session stats

Practice mode shows Practice badge instead of rating

Hint usage shown on completion

Puzzle Rocket session-end shows all stats

GM Move session-end shows accuracy

Continue button advances to next puzzle

View Solution button shows correct moves

Play Again starts fresh session

Back to Menu returns to mode selection

Puzzle rating shown on completion

Time spent shown on completion

Default rating range applied

Rating range clamps when min exceeds max

Start without theme selection works

Theme selection toggle and Select All

Rating slider steps by 100

Start game failure shows error

Coming Soon when mode not available

Rating range persists while toggling themes

Puzzle rating updates on solve (not just user)

Puzzle rating updates on fail

Empty puzzle database for filter

Very long session memory handling

User at minimum rating (100) cannot go lower

User at maximum rating (3500) cannot go higher

Network disconnect during puzzle

Session timeout after inactivity

Rapid consecutive moves

Back button during puzzle

Same puzzle served twice in session

Puzzle with very long solution (10+ moves)

Timer at exactly 0 (boundary)

Move submitted at exact timer expiry

Hint on final move of puzzle

User has identical rating to puzzle

Extremely low RD (high confidence)

Extremely high RD (new player)

Unicode in puzzle data

Stalemate position in puzzle

Start button disabled until account selected

Selecting Chess.com enables Start

Selecting Lichess enables Start

Switching accounts updates selection

Start navigates to play route

Selection resets after page reload

Account cards display logos and labels

Connected state uses correct styling

Glicko rating system used for rated modes

Only Puzzle Tempo and Puzzle Climb are rated

Both user and puzzle ratings update on solve

Both user and puzzle ratings update on fail

Rating range selection triggers practice mode

Rating clamped at minimum 100

Rating clamped at maximum 3500

One hint maximum per puzzle

Hint highlights piece to move only

Hint reduces rating gain by 50%

Hint does not affect rating loss

Hints unavailable in Puzzle Rocket

Hint resets between puzzles

Hint on multi-move puzzle highlights NEXT move

Single-move puzzle completes after one move

Multi-move puzzle requires all moves

Wrong move fails puzzle immediately

Multi-move length does NOT affect rating

RD decreases after rated activity

Provisional rating indicator shown

Concurrent session prevention

Puzzle Rocket shows session-end screen only

GM Move shows session-end screen only

Other modes show puzzle-end completion

GM Move is unrated

Board shows position from PGN

User guesses next move

Correct guess feedback

Wrong guess shows actual GM move

Hints available in GM Move

Session-end shows accuracy summary

No per-move completion modal

Game selection screen shows available games

Filter by Grandmaster

Filter by Opening

Play button navigates to game

Search input works

Layout is responsive

Game starts at midgame position

Admin uploads PGN with metadata

Sequence ends after defined moves

User can exit mid-game

Opening label displayed if available

Accuracy calculation is correct

Opening Puzzles is unrated

Opening filter works

Rating range filter works

Combined opening AND rating filter

Wrong move fails puzzle

Session continues after failure

Hints allowed with no impact

Puzzle-end completion screen shown

Coming Soon when mode not available

Banner renders correctly

Empty filter results handled

Multiple opening selection works

Session continues after failure

User can exit session anytime

Session-end shows puzzle-end screen

Step Size calculation is correct

Index generation is correct

Rating ranges use offset correctly

Puzzle selected randomly from range

Handles Number of Puzzles = 0 gracefully

Retry when no puzzle in range

Max retries limit enforced

Negative Start Rating handled

Start Rating > End Rating handled

Very large Number of Puzzles handled

Puzzle Rocket is unrated

1-minute duration ends at exactly 60 seconds

2-minute duration ends at exactly 120 seconds

3-minute duration ends at exactly 180 seconds

Survival mode has no time limit

Wrong move fails puzzle immediately

First failure shows 1/3

Third failure ends game immediately

Hints are NOT available in Puzzle Rocket

Timer expiry ends session

Ramp-Up Formula applied to puzzle selection

Failure counter resets between sessions

No puzzle-end modal in Puzzle Rocket

Session-end screen shows correct statistics

Personal bests tracked (Today, Week, All Time)

Duration options empty shows unavailable state

Simultaneous 3rd failure and timer expiry

Browser refresh during timed session

Duration selection UI shows all options

Survival mode displays fire icon

Game ends on timeout even with strikes remaining

Start game API error surfaces to user

Give Up button ends game immediately

Play Again restarts with same settings

New Game returns to settings

Puzzles drawn from all themes

Longest streak tracked correctly

Average time per puzzle calculated

Puzzle Tempo is rated (Glicko)

Tactical theme filtering works

Multiple theme filtering (OR logic)

No theme selection defaults to all themes

Wrong move fails puzzle immediately

Fast solve gets maximum SCORE (time bonus)

Slow solve gets reduced SCORE (time decay)

Glicko rating gain is NOT affected by solve time

Hint reduces Glicko rating gain by 50%

Streak multiplier increases game score

Incorrect attempt resets streak and scores 0

User exit ends session

Session continues indefinitely until exit

Puzzle-end completion screen shown

Rating range selection triggers practice mode

Start without rating prompts initialization

Theme selection toggle and Select All

Ramp-Up Formula applied

Rating check failure shows error

Start game failure shows error

Board orientation can be flipped

Legal move highlights shown

Last move highlighted on board

Correct move shows green feedback

Wrong move shows red feedback

Keyboard shortcuts work

Sound effects can be toggled

Board piece set can be changed

Board theme can be changed

Move history displayed

Rating display updates in real-time

Timer display accurate (Puzzle Rocket)

Failure counter visible (Puzzle Rocket)

Hint button shows remaining hints

Loading state shown while fetching puzzle

Responsive layout on different screen sizes

Dark mode support

Promotion dialog appears

Check indicator shown

Captured pieces shown

User navigates puzzle with keyboard only

User uses screen reader with puzzle

User with color blindness plays puzzle

User increases text size

User with motor impairment uses large click targets

User with cognitive disability uses clear interface

User pauses timed puzzle (if feature exists)

User disables animations

User in high contrast mode

User uses voice control

User plays daily puzzle

User sees daily puzzle streak

User loses daily streak

User compares daily puzzle time with friends

User plays weekly puzzle challenge

User participates in puzzle tournament

User receives puzzle reminder notification

User views past daily puzzles

User completes monthly puzzle challenge

User plays themed event puzzles

New user plays first puzzle ever

User plays complete Puzzle Rocket session (1 minute)

User plays Puzzle Rocket Survival until game over

User plays rated Puzzle Tempo session with themes

User plays Puzzle Tempo in practice mode (rating range selected)

User plays Puzzle Climb and sees difficulty adapt

User uses hint in rated mode

User plays Calculation Mode - Deep Think

User plays Calculation Mode - Commitment

User plays Calculation Mode - Checkmate Climb

User plays Opening Puzzles filtered by specific opening

User plays Guess the Grandmaster Move

User fails a puzzle and sees correct solution

User completes multi-move puzzle with opponent responses

User quits session mid-puzzle

User views their puzzle statistics

User returns to continue previous session (if applicable)

User plays on mobile device

User experiences rating progression over multiple sessions

User explores all puzzle modes from menu

User loses internet connection during puzzle

User session expires during puzzle

User refreshes page during timed puzzle

User navigates back button during session

User encounters server error

User double-clicks move too fast

User tries to move during opponent's turn

User on very slow connection

User browser crashes during rated puzzle

User on unsupported browser

User encounters puzzle that fails to load

User on mobile rotates device mid-puzzle

User has JavaScript disabled

User opens puzzle in multiple tabs

User's clock differs from server

User moves piece by drag and drop

User moves piece by click-click

User attempts illegal move

User moves piece on touch device

User sees opponent's response animated

User flips board orientation

User views move history during puzzle

User uses keyboard controls

User promotes pawn

User makes castling move

User makes en passant capture

User sees check and checkmate indicators

User sees correct/incorrect move feedback

User adjusts audio settings

User adjusts board theme/colors

User right-clicks to draw arrows/highlight

User gives up on puzzle

User retries failed puzzle (if available)

User shares puzzle with friend

User reports incorrect puzzle

New user sees puzzle tutorial on first visit

User can replay tutorial from help menu

New user plays guided first puzzle

User sees mode introduction on first selection

User sets initial skill level

User links external chess rating

Guest user can play puzzles without account

User sees tooltips on hover for UI elements

User accesses help/FAQ during puzzle

User understands rating confidence/provisional

User reviews failed puzzle with solution

User analyzes completed puzzle position

User bookmarks puzzle for later review

User views puzzle explanation/annotation

User sees related puzzles by theme

User retries failed puzzle immediately

User views puzzle difficulty after completion

User sees solve statistics for puzzle

User practices specific weakness

User compares solve to previous attempt

User reviews entire session performance

User exports puzzle as PGN/image

User changes board theme

User changes piece set

User enables/disables move sounds

User enables/disables notifications

User enables dark mode