⚡ Code Royale: JavaScript Piscine Practice & Battle Royale Arena

An interactive, zero-dependency, native JavaScript drill engine, browser code arena, and capstone project runtime designed to take you from absolute ground zero to full mastery of JavaScript language mechanics through 277 bite-sized micro-lessons and cumulative mini-projects.

👉 Play Live in Browser: https://js-mastery-livid.vercel.app/

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🎮 Two Ways to Practice

Mode 1: The "Code Royale" Web Application (Browser Experience)

Experience JavaScript coding as a competitive esports arena and interactive learning workspace:

• 🔥 Sequential "Piscine Gauntlet" (Beginner to Legend): Practice from Challenge #01 (01-constant-variable) through #277 in strict sequence against adaptive rival coders with sudden-death timers and coin bounties.
• ⚔️ 8-Player Battle Royale: 8 developers enter, 3 elimination rounds, and the last programmer standing claims the 8x jackpot pot.
• 🎯 1v1 High-Stakes Duel: Sudden-death head-to-head match where the fastest coder to pass assertions wins double stakes.
• 🗺️ Interactive 277-Level Curriculum Map across 10 Acts: Browse all 10 learning modules, track unlocked/completed levels, and jump directly into any challenge.
• 🚀 7 Cumulative Capstone Mini-Projects (Act 9): Put modular skills together to write complex engines (Matrix search, Sort analyzers, Curried pipelines, Reactive Proxies, and Async schedulers).
• 👤 Persistent Player Profiles & Accounts: Choose your hacker avatar, track MMR, coin balances, and level progression in localStorage.
• 🛡️ In-Browser Safe Sandbox: Real-time evaluation of ES Module code with loop timeout protection and virtual assertion console.
• 🔊 Procedural Web Audio Engine: Zero-dependency audio synthesizer generating real-time countdown ticks, coin clinks, elimination drops, and victory fanfares.

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Mode 2: High-Velocity Terminal CLI (VS Code / Terminal)

A focused, zero-clutter terminal drill environment featuring automatic challenge promotion and auto-switching solution.js:

• 📝 Single Active File: Leave solution.js open in your editor. Whenever your code passes, solution.js automatically reloads with the next challenge's starter code.
• 🚀 Auto-Promotion: Every time your test passes, you are instantly advanced to the next level without touching folder trees.
• ⚡ Live Watch Engine: Run npm run watch — save your file (Cmd + S) and watch it test, pass, and switch to the next quest in real time.

# 1. Step-by-step interactive drill runner (auto-promotes and switches solution.js):
npm start
# or: npm run drill

# 2. Live auto-detecting watch mode (re-tests, promotes & switches on save):
npm run watch

# 3. Test current active challenge (evaluates & promotes):
npm test
# or: npm run current

# 4. Launch local web server:
npm run app
# or: npm run serve

# 5. Reset all 277 challenge files to starter comment stubs:
npm run reset

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🏗️ 7 Cumulative Capstone Mini-Projects (Act 9: Challenges 217–247)

Act 9 transitions learners from micro-drills to building modular production-grade subsystems:

1. Math & Number Theory Engine (divisors, evenSum, isPerfectNum, palindromicChain, factorial, fibonacci): High-performance numerical analysis algorithms, recursion, and sequence generation.
2. Matrix & 2D Grid Pattern Search Engine (sentencePyramid, gridWordsFinder, gridWordFinder2, isSnakePath): 2D coordinate spatial navigation, backtracking word search in 8 directions, and path validation.
3. Sorting Analyzer & Nested Data Transformer (reverseChunks, nestedArrayReverser, bubbleSortAnalyzer, insertionSortAnalyzer): Deep array partition inversion, recursive tree flattening, and algorithmic comparison & swap tracking.
4. Deep Object Toolkit & Schema Transformation Suite (deepClone, deepEqual, deepFind, deepFreeze, flattenObject, flattenAndMap, transformKeys, mergeAndTransform, examGrader): Enterprise recursive object traversal, cycle-safe cloning, dot-path resolution, schema key formatting, and analytics.
5. Functional Composition & Pipeline Runtime (createCurriedCharacterCreator, createCurriedFilterAndMap, pipeline): Higher-order closure chaining, factory generators, and dynamic multi-stage data pipelines.
6. Reactive State & Proxy Interceptor Engine (swappableObject, trapObject): Metaprogramming with ES6 Proxies, property mutation interception, dynamic key virtualization, and state swapping.
7. Asynchronous Race & Resilience Scheduler (FinalAttempt, sleepBreaker, zooRace): Exponential retry resilience, concurrency racing, and async generator coordination.

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🏛️ Act 10: Multi-Concept Production Subsystems & Grand Capstones (Challenges 248–277)

Act 10 challenges combine 3 to 5 core JavaScript primitives (closures, proxies, async queues, AST parsing, cryptography, dynamic programming, and state machines) into fully integrated production engines:

1. Track 1: Data Pipelines & Query Engines (fluentQuery, validateSchema, csvToJson, deduplicateRecords, createLens): Composable query builders, schema sanitization, CSV parsing, and deep immutable path lenses.
2. Track 2: State Machines & Event Brokers (createStateMachine, createEventBroker, createHistoryManager, createSignalStore, createPipeline): Deterministic FSM with transition guards, wildcard pub/sub bus, multi-step undo/redo, reactive signal dependency graphs, and onion-model middleware.
3. Track 3: Resilience, Queues & Concurrency (createTaskQueue, createAsyncCache, createBatchDispatcher, createCircuitBreaker, promisePool): Token-bucket rate limiting, TTL cache with thundering-herd defense, automatic batch dispatching, circuit breaker fault tolerance, and bounded parallel concurrency.
4. Track 4: Compilers, Parsers & Math Models (compileMarkdown, evaluateExpression, renderTemplate, createTokenBucket, fuzzySearch): Zero-dependency markdown parser, Dijkstra's Shunting-Yard arithmetic engine, Handlebars-style template interpolation, and Levenshtein distance fuzzy search.
5. Track 5: Security, Encoding & Cache Policies (verifyJWT, compressText, createJsonPatch, createDualCache, createHashChain): HMAC-SHA256 JWT verifier, RLE & frequency text compression, RFC 6902 JSON patch engine, LRU/LFU dual eviction cache, and cryptographic blockchain audit chains.
6. Track 6: Culminating Capstones (createReduxStore, createSqlEngine, createVNode & diffing, createContainer, createKanbanEngine): Micro-Redux unidirectional state, in-memory relational SQL engine (SELECT, JOIN, GROUP BY, ORDER BY), Virtual DOM diffing & reconciliation, Inversion of Control (IoC) DI container, and full reactive Kanban project management engine.

🗺️ 277-Stage Complete JavaScript Curriculum (Acts 1–10)

#	Challenge Folder	Concept	Directory
001	01-constant-variable	01 — Constant Variable & Export	01-constant-variable
002	02-basic-function	02 — Basic Function & Console Output	02-basic-function
003	03-function-parameter	03 — Function Parameter	03-function-parameter
004	04-return-statement	04 — Return Statement	04-return-statement
005	05-return-parameter	05 — Returning a Parameter (Identity Function)	05-return-parameter
006	06-primitive-string	06 — String Primitive	06-primitive-string
007	07-primitive-number	07 — Number Primitive	07-primitive-number
008	08-primitive-boolean	08 — Boolean Primitive	08-primitive-boolean
009	09-primitive-undefined	09 — Undefined Primitive	09-primitive-undefined
010	10-primitive-null	10 — Null Primitive	10-primitive-null
011	11-escape-characters	11 — Escape Characters in Strings	11-escape-characters
012	12-template-literals	12 — Template Literals & Interpolation	12-template-literals
013	13-string-length	13 — String Length Property	13-string-length
014	14-string-char-at	14 — String charAt Method	14-string-char-at
015	15-string-at-method	15 — String at Method (.at())	15-string-at-method
016	16-string-primitive-vs-object	16 — String Primitives vs String Objects	16-string-primitive-vs-object
017	17-string-raw	17 — String.raw Static Method	17-string-raw
018	18-string-concat	18 — String Concatenation (+ and .concat())	18-string-concat
019	19-increment	19 — Increment Function	19-increment
020	20-decrement	20 — Decrement Function	20-decrement
021	21-addition	21 — Addition Operator (+)	21-addition
022	22-subtraction	22 — Subtraction Operator (-)	22-subtraction
023	23-multiplication	23 — Multiplication Operator (*)	23-multiplication
024	24-division	24 — Division Operator (/)	24-division
025	25-remainder	25 — Remainder / Modulo Operator (%)	25-remainder
026	26-exponentiation	26 — Exponentiation Operator (**)	26-exponentiation
027	27-unary-plus	27 — Unary Plus Operator (+)	27-unary-plus
028	28-unary-negation	28 — Unary Negation Operator (-)	28-unary-negation
029	29-addition-assignment	29 — Addition Assignment (+=)	29-addition-assignment
030	30-multiplication-assignment	30 — Multiplication Assignment (*=)	30-multiplication-assignment
031	31-logical-and-assignment	31 — Logical AND Assignment (&&=)	31-logical-and-assignment
032	32-logical-or-assignment	32 — Logical OR Assignment (
033	33-nullish-assignment	33 — Nullish Coalescing Assignment (??=)	33-nullish-assignment
034	34-strict-equality	34 — Strict Equality (===)	34-strict-equality
035	35-strict-inequality	35 — Strict Inequality (!==)	35-strict-inequality
036	36-greater-than	36 — Greater Than Operator (>)	36-greater-than
037	37-less-than	37 — Less Than Operator (<)	37-less-than
038	38-greater-or-equal	38 — Greater Than or Equal (>=)	38-greater-or-equal
039	39-less-or-equal	39 — Less Than or Equal (<=)	39-less-or-equal
040	40-in-operator	40 — The 'in' Operator	40-in-operator
041	41-instanceof-operator	41 — The 'instanceof' Operator	41-instanceof-operator
042	42-logical-not	42 — Logical NOT Operator (!)	42-logical-not
043	43-double-not	43 — Double NOT (!!) for Truthiness	43-double-not
044	44-logical-and	44 — Logical AND Operator (&&)	44-logical-and
045	45-logical-or	45 — Logical OR Operator (
046	46-nullish-coalescing	46 — Nullish Coalescing Operator (??)	46-nullish-coalescing
047	47-ternary-operator	47 — Conditional (Ternary) Operator (? :)	47-ternary-operator
048	48-object-literal	48 — Object Initializer Syntax	48-object-literal
049	49-dynamic-get	49 — Dynamic Property Lookup	49-dynamic-get
050	50-dynamic-set	50 — Dynamic Property Assignment	50-dynamic-set
051	51-delete-operator	51 — The 'delete' Operator	51-delete-operator
052	52-optional-chaining	52 — Optional Chaining (?.)	52-optional-chaining
053	53-object-reference	53 — Object References in Memory	53-object-reference
054	54-freeze-object	54 — Freezing an Object	54-freeze-object
055	55-deep-freeze	55 — Deep Object Immutability	55-deep-freeze
056	56-clone-assign	56 — Shallow Cloning with Object.assign	56-clone-assign
057	57-clone-spread	57 — Shallow Cloning with Spread Operator	57-clone-spread
058	58-circular-reference	58 — Circular Object Reference	58-circular-reference
059	59-array-literal	59 — Array Initializer Syntax	59-array-literal
060	60-first-element	60 — Zero-Based Indexing (First Element)	60-first-element
061	61-last-element	61 — Last Element Indexing	61-last-element
062	62-array-push-pop	62 — Array Mutation: push & pop	62-array-push-pop
063	63-array-spread	63 — Array Spread Syntax ([...arr])	63-array-spread
064	64-freeze-array	64 — Freezing an Array	64-freeze-array
065	65-array-destructuring	65 — Array Destructuring	65-array-destructuring
066	66-object-destructuring	66 — Object Destructuring	66-object-destructuring
067	67-while-counter	67 — While Loop (Counter)	67-while-counter
068	68-while-accumulate	68 — While Loop (Accumulator)	68-while-accumulate
069	69-for-loop-counter	69 — Standard For Loop	69-for-loop-counter
070	70-for-of-array	70 — For..Of Loop (Array Iteration)	70-for-of-array
071	71-for-of-string	71 — For..Of Loop (String Search & Counting)	71-for-of-string
072	72-for-in-object	72 — For..In Loop (Object Keys)	72-for-in-object
073	73-break-continue	73 — Loop Control (break & continue)	73-break-continue
074	74-recursion-counter	74 — Recursion (Counter)	74-recursion-counter
075	75-recursion-accumulate	75 — Recursion (Accumulator)	75-recursion-accumulate
076	76-recursion-factorial	76 — Recursion (Factorial)	76-recursion-factorial
077	77-multiply-without-operator	77 — Repeated Addition Multiplication	77-multiply-without-operator
078	78-multiply-recursive	78 — Recursive Multiplication	78-multiply-recursive
079	79-string-split	79 — Splitting Strings (.split())	79-string-split
080	80-string-join	80 — Joining Arrays into Strings (.join())	80-string-join
081	81-string-uppercase	81 — Uppercase Transformation (.toUpperCase())	81-string-uppercase
082	82-string-lowercase	82 — Lowercase Transformation (.toLowerCase())	82-string-lowercase
083	83-string-capitalize	83 — String Capitalization	83-string-capitalize
084	84-jaden-case	84 — Jaden Casing Strings	84-jaden-case
085	85-string-cut-first	85 — Cut First Characters (cutFirst)	85-string-cut-first
086	86-string-cut-last	86 — Cut Last Characters (cutLast)	86-string-cut-last
087	87-string-cut-first-last	87 — Cut First & Last (cutFirstLast)	87-string-cut-first-last
088	88-string-keep-first	88 — Keep First Characters (keepFirst)	88-string-keep-first
089	89-string-keep-last	89 — Keep Last Characters (keepLast)	89-string-keep-last
090	90-string-repeat	90 — String Repeat (.repeat())	90-string-repeat
091	91-string-includes	91 — String Inclusion Check (.includes())	91-string-includes
092	92-string-starts-with	92 — Prefix Check (.startsWith())	92-string-starts-with
093	93-string-ends-with	93 — Suffix Check (.endsWith())	93-string-ends-with
094	94-string-index-of	94 — Finding Substring Index (.indexOf())	94-string-index-of
095	95-string-last-index-of	95 — Last Substring Occurrence (.lastIndexOf())	95-string-last-index-of
096	96-string-slice	96 — Slicing Strings (.slice())	96-string-slice
097	97-string-substring	97 — Extracting with .substring()	97-string-substring
098	98-string-trim	98 — Trimming Whitespace (.trim())	98-string-trim
099	99-string-trim-start-end	99 — Trimming Start & End (.trimStart & .trimEnd)	99-string-trim-start-end
100	100-string-pad-start	100 — Padding Start (.padStart())	100-string-pad-start
101	101-string-pad-end	101 — Padding End (.padEnd())	101-string-pad-end
102	102-string-replace	102 — Replacing Substrings (.replace())	102-string-replace
103	103-string-replace-all	103 — Replacing All Substrings (.replaceAll())	103-string-replace-all
104	104-string-char-code-at	104 — Character Code (.charCodeAt())	104-string-char-code-at
105	105-string-from-char-code	105 — String.fromCharCode Static Method	105-string-from-char-code
106	106-string-code-point-at	106 — Unicode Code Point (.codePointAt())	106-string-code-point-at
107	107-string-from-code-point	107 — String.fromCodePoint Static Method	107-string-from-code-point
108	108-string-case-insensitive-compare	108 — Case-Insensitive String Equality	108-string-case-insensitive-compare
109	109-string-locale-compare	109 — Locale-Aware Comparison (.localeCompare())	109-string-locale-compare
110	110-string-is-well-formed	110 — Well-Formed Unicode Strings (.isWellFormed())	110-string-is-well-formed
111	111-math-floor-ceil	111 — Math.floor & Math.ceil	111-math-floor-ceil
112	112-math-round-trunc	112 — Math.round & Math.trunc	112-math-round-trunc
113	113-math-max-min	113 — Math.max & Math.min	113-math-max-min
114	114-math-abs	114 — Math.abs Function	114-math-abs
115	115-math-sqrt-pow	115 — Math.sqrt & Math.pow	115-math-sqrt-pow
116	116-math-random-range	116 — Random Number Range (Math.random)	116-math-random-range
117	117-number-parse-int	117 — Number.parseInt Function	117-number-parse-int
118	118-number-parse-float	118 — Number.parseFloat Function	118-number-parse-float
119	119-number-is-integer	119 — Number.isInteger Type Guard	119-number-is-integer
120	120-number-is-finite	120 — Number.isFinite Type Guard	120-number-is-finite
121	121-array-shift	121 — Array Mutation: shift()	121-array-shift
122	122-array-unshift	122 — Array Mutation: unshift()	122-array-unshift
123	123-array-splice	123 — Array Splicing (.splice())	123-array-splice
124	124-array-reverse	124 — Array Reversing (.reverse())	124-array-reverse
125	125-array-fill	125 — Array Fill (.fill())	125-array-fill
126	126-array-for-each	126 — Array Iteration (.forEach())	126-array-for-each
127	127-array-map	127 — Array Transformation (.map())	127-array-map
128	128-array-filter	128 — Array Filtering (.filter())	128-array-filter
129	129-array-reduce	129 — Array Reduction (.reduce())	129-array-reduce
130	130-array-reduce-right	130 — Right-to-Left Reduction (.reduceRight())	130-array-reduce-right
131	131-array-find	131 — Finding an Element (.find())	131-array-find
132	132-array-find-index	132 — Finding Element Index (.findIndex())	132-array-find-index
133	133-array-some	133 — Array Predicate Check (.some())	133-array-some
134	134-array-every	134 — Universal Predicate Check (.every())	134-array-every
135	135-array-includes	135 — Array Inclusion Check (.includes())	135-array-includes
136	136-array-sort	136 — Array Sorting (.sort())	136-array-sort
137	137-array-flat	137 — Array Flattening (.flat())	137-array-flat
138	138-array-flat-map	138 — Array FlatMap (.flatMap())	138-array-flat-map
139	139-array-of	139 — Array.of Static Method	139-array-of
140	140-object-keys	140 — Object.keys Function	140-object-keys
141	141-object-values	141 — Object.values Function	141-object-values
142	142-object-entries	142 — Object.entries Function	142-object-entries
143	143-object-has-own	143 — Object.hasOwn Function	143-object-has-own
144	144-deep-get	144 — Deep Property Lookup (deepGet)	144-deep-get
145	145-deep-set	145 — Deep Property Assignment (deepSet)	145-deep-set
146	146-set-data-structure	146 — Set Data Structure (Unique Collections)	146-set-data-structure
147	147-map-data-structure	147 — Map Data Structure (Key-Value Map)	147-map-data-structure
148	148-map-to-object	148 — Map to Plain Object (Object.fromEntries)	148-map-to-object
149	149-object-to-map	149 — Plain Object to Map	149-object-to-map
150	150-bitwise-and	150 — Bitwise AND Operator (&)	150-bitwise-and
151	151-bitwise-or	151 — Bitwise OR Operator (	)
152	152-bitwise-xor	152 — Bitwise XOR Operator (^)	152-bitwise-xor
153	153-bitwise-not	153 — Bitwise NOT Operator (~)	153-bitwise-not
154	154-bitwise-left-shift	154 — Bitwise Left Shift (<<)	154-bitwise-left-shift
155	155-bitwise-right-shift	155 — Bitwise Right Shift (>>)	155-bitwise-right-shift
156	156-callback-apply	156 — Passing Functions as Values (Callbacks)	156-callback-apply
157	157-arrow-function	157 — Arrow Functions	157-arrow-function
158	158-default-parameters	158 — Default Function Parameters	158-default-parameters
159	159-rest-parameters	159 — Rest Parameters (...args)	159-rest-parameters
160	160-function-closure	160 — Closures (Private State)	160-function-closure
161	161-currying	161 — Currying Functions	161-currying
162	162-memoization	162 — Memoization Pattern	162-memoization
163	163-function-composition	163 — Function Composition (pipe)	163-function-composition
164	164-class-declaration	164 — Class Declarations	164-class-declaration
165	165-class-methods	165 — Class Instance Methods	165-class-methods
166	166-class-getters-setters	166 — Getters and Setters	166-class-getters-setters
167	167-class-inheritance	167 — Class Inheritance (extends & super)	167-class-inheritance
168	168-class-static-methods	168 — Static Methods	168-class-static-methods
169	169-try-catch	169 — Error Handling with try..catch	169-try-catch
170	170-throw-error	170 — Throwing Errors	170-throw-error
171	171-promise-resolve	171 — Promises (Promise.resolve)	171-promise-resolve
172	172-async-sleep	172 — Asynchronous Sleep (setTimeout Promise)	172-async-sleep
173	173-async-await	173 — Async / Await Syntax	173-async-await
174	174-promise-all	174 — Concurrency with Promise.all	174-promise-all
175	175-promise-race	175 — First Settled with Promise.race	175-promise-race
176	176-promise-all-settled	176 — Complete Outcomes with Promise.allSettled	176-promise-all-settled
177	177-event-emitter	177 — Event Emitter Pattern (Pub/Sub)	177-event-emitter
178	178-async-generator	178 — Async Generators (async function*)	178-async-generator
179	179-for-await-of	179 — Async Iteration (for await..of)	179-for-await-of
180	180-dog-years	180 — Domain Modeling: Dog Years	180-dog-years
181	181-physics-acceleration	181 — Domain Modeling: Physics Acceleration	181-physics-acceleration
182	182-super-type-of	182 — Reflection: superTypeOf	182-super-type-of
183	183-hash-code	183 — Algorithms: 32-Bit Polynomial Hash	183-hash-code
184	184-block-chain	184 — Closures: Chained Blockchain Node	184-block-chain
185	185-chunk-array	185 — Project Utility: Array Chunking	185-chunk-array
186	186-group-by	186 — Project Utility: Group By	186-group-by
187	187-deep-clone	187 — Project Utility: Deep Clone	187-deep-clone
188	188-query-string-parse	188 — Project Utility: URL Query String Parser	188-query-string-parse
189	189-query-string-stringify	189 — Project Utility: URL Query String Serializer	189-query-string-stringify
190	190-debounce-function	190 — Project Utility: Debounce Pattern	190-debounce-function
191	191-throttle-function	191 — Project Utility: Throttle Pattern	191-throttle-function
192	192-async-retry	192 — Project Utility: Async Retry Wrapper	192-async-retry
193	193-data-validator	193 — Project Utility: Schema Validator	193-data-validator
194	194-html-builder	194 — Project Utility: HTML Element Generator	194-html-builder
195	195-biggie-smalls	195 — Numeric Boundaries: Biggie Smalls	195-biggie-smalls
196	196-sign	196 — Signum Evaluation: sign	196-sign
197	197-same-sign	197 — Sign Parity: sameSign	197-same-sign
198	198-kiss	198 — Index Swapping: kiss	198-kiss
199	199-keep-first-last	199 — Boundary Slicing: keepFirstLast	199-keep-first-last
200	200-elementary-divide	200 — Arithmetic Algorithm: Repeated Subtraction Division	200-elementary-divide
201	201-elementary-modulo	201 — Arithmetic Algorithm: Repeated Subtraction Modulo	201-elementary-modulo
202	202-nasa	202 — Number Formatting: nasa	202-nasa
203	203-triangle	203 — Nested Loops: Triangle Pattern	203-triangle
204	204-pyramid	204 — Layout Algorithms: Pyramid Pattern	204-pyramid
205	205-molecules-dna	205 — Genetic Transcription: RNA to DNA	205-molecules-dna
206	206-molecules-rna	206 — Genetic Transcription: DNA to RNA	206-molecules-rna
207	207-reverser-manual	207 — Manual Reversal: reverse	207-reverser-manual
208	208-slicer-manual	208 — Index Normalization: Manual slice	208-slicer-manual
209	209-unbreakable-split	209 — Parsing Algorithms: Manual split	209-unbreakable-split
210	210-unbreakable-join	210 — Formatting Algorithms: Manual join	210-unbreakable-join
211	211-find-expression	211 — Backtracking Search: findExpression	211-find-expression
212	212-sums-partition	212 — Backtracking Algorithms: Integer Partitions (sums)	212-sums-partition
213	213-cut-corners-trunc	213 — Numerical Approximation: Custom trunc	213-cut-corners-trunc
214	214-cut-corners-round	214 — Numerical Approximation: Custom round	214-cut-corners-round
215	215-is-namespace	215 — Type Guard Namespace: is	215-is-namespace
216	216-collections-conversions	216 — Cross-Collection Conversions	216-collections-conversions
217	217-reverse-chunks	217 — Checkpoint: Array Reverse Chunks	217-reverse-chunks
218	218-bubble-sort-analyzer	218 — Checkpoint: Bubble Sort Analyzer	218-bubble-sort-analyzer
219	219-curried-character-creator	219 — Checkpoint: Curried Character Maker	219-curried-character-creator
220	220-deep-clone-advanced	220 — Checkpoint: Advanced Deep Clone	220-deep-clone-advanced
221	221-deep-equal	221 — Checkpoint: Deep Equal Comparison	221-deep-equal
222	222-deep-find	222 — Checkpoint: Deep Property Finder	222-deep-find
223	223-deep-freeze-recursive	223 — Checkpoint: Deep Freeze Immutability	223-deep-freeze-recursive
224	224-divisor-finder	224 — Checkpoint: Divisor Finder	224-divisor-finder
225	225-election-mix	225 — Checkpoint: Curried Filter and Map	225-election-mix
226	226-even-sum	226 — Checkpoint: Even Numbers Summation	226-even-sum
227	227-exam-grader	227 — Checkpoint: Exam Grader Analytics	227-exam-grader
228	228-factorial-recursive	228 — Checkpoint: Factorial Sequence	228-factorial-recursive
229	229-fibonacci-sequence	229 — Checkpoint: Fibonacci Generator	229-fibonacci-sequence
230	230-final-attempt	230 — Checkpoint: Final Attempt Async Retry	230-final-attempt
231	231-flatten-and-map	231 — Checkpoint: Flatten and Map Objects	231-flatten-and-map
232	232-flatten-object	232 — Checkpoint: Flatten Nested Object	232-flatten-object
233	233-grid-words-finder	233 — Checkpoint: Grid Words Finder (Horizontal & Vertical)	233-grid-words-finder
234	234-grid-words-finder-2	234 — Checkpoint: Grid Word Finder 2 (8 Directions)	234-grid-words-finder-2
235	235-insertion-sort-analyzer	235 — Checkpoint: Insertion Sort Analyzer	235-insertion-sort-analyzer
236	236-nested-array-reverser	236 — Checkpoint: Deep Nested Array Reverser	236-nested-array-reverser
237	237-object-lab	237 — Checkpoint: Object Lab (Merge & Transform)	237-object-lab
238	238-palindromic-chain	238 — Checkpoint: Palindromic Chain (196 Algorithm)	238-palindromic-chain
239	239-perfect-number	239 — Checkpoint: Perfect Number Validator	239-perfect-number
240	240-functional-pipeline	240 — Checkpoint: Functional Pipeline with Audit Trace	240-functional-pipeline
241	241-sentence-pyramid	241 — Checkpoint: Sentence Pyramid	241-sentence-pyramid
242	242-sleep-breaker	242 — Checkpoint: Sleep Breaker Asynchronous Timer	242-sleep-breaker
243	243-snake-path-validator	243 — Checkpoint: Snake Path Validator (No Loops)	243-snake-path-validator
244	244-swappable-object	244 — Checkpoint: Swappable Proxy Object	244-swappable-object
245	245-transform-keys	245 — Checkpoint: Recursive Key Transformer	245-transform-keys
246	246-trap-object	246 — Checkpoint: Trap Object Interceptor	246-trap-object
247	247-zoo-race	247 — Checkpoint: Zoo Race Physics Simulation	247-zoo-race
248	248-fluent-query-builder	248 — Multi-Concept: Fluent Query Builder (Pipelines & Aggregation)	248-fluent-query-builder
249	249-schema-validator-sanitizer	249 — Multi-Concept: Schema Validator & Sanitizer (Recursion & Types)	249-schema-validator-sanitizer
250	250-csv-json-bidirectional-parser	250 — Multi-Concept: Bidirectional CSV/JSON Parser (Streaming & Parsing)	250-csv-json-bidirectional-parser
251	251-data-dedup-merge-engine	251 — Multi-Concept: Deduplication & Merge Engine (Composite Keys)	251-data-dedup-merge-engine
252	252-nested-object-path-lens	252 — Multi-Concept: Nested Object Path Lens (Immutability & Traversal)	252-nested-object-path-lens
253	253-finite-state-machine	253 — Multi-Concept: Finite State Machine (Guards & Lifecycle Hooks)	253-finite-state-machine
254	254-wildcard-event-broker	254 — Multi-Concept: Wildcard Event Broker (Pub/Sub & Glob Patterns)	254-wildcard-event-broker
255	255-undo-redo-history-manager	255 — Multi-Concept: Undo/Redo History Manager (Stacks & Snapshots)	255-undo-redo-history-manager
256	256-reactive-store-signals	256 — Multi-Concept: Reactive Store & Signals (Dependency Tracking)	256-reactive-store-signals
257	257-observer-middleware-pipeline	257 — Multi-Concept: Async Middleware Pipeline (Onion Model Execution)	257-observer-middleware-pipeline
258	258-rate-limited-task-queue	258 — Multi-Concept: Rate-Limited Task Queue (Concurrency & Windows)	258-rate-limited-task-queue
259	259-async-cache-ttl	259 — Multi-Concept: Async Cache with TTL (Thundering Herd Defense)	259-async-cache-ttl
260	260-batch-request-dispatcher	260 — Multi-Concept: Batch Request Dispatcher (Debouncing & Promises)	260-batch-request-dispatcher
261	261-circuit-breaker-guard	261 — Multi-Concept: Circuit Breaker Guard (Resilience & Probing)	261-circuit-breaker-guard
262	262-promise-concurrency-pool	262 — Multi-Concept: Promise Concurrency Pool (Bounded Parallelism)	262-promise-concurrency-pool
263	263-markdown-micro-compiler	263 — Multi-Concept: Markdown Micro-Compiler (AST & HTML Rendering)	263-markdown-micro-compiler
264	264-shunting-yard-evaluator	264 — Multi-Concept: Shunting-Yard Evaluator (Infix/RPN Math Engine)	264-shunting-yard-evaluator
265	265-template-directive-engine	265 — Multi-Concept: Template Directive Engine (Interpolation & Loops)	265-template-directive-engine
266	266-token-bucket-rate-limiter	266 — Multi-Concept: Token Bucket Rate Limiter (Burst Leaky Bucket)	266-token-bucket-rate-limiter
267	267-levenshtein-fuzzy-search	267 — Multi-Concept: Levenshtein Fuzzy Search (Dynamic Programming)	267-levenshtein-fuzzy-search
268	268-jwt-token-verifier	268 — Multi-Concept: JWT Token Verifier & Signer (Crypto HMAC-SHA256)	268-jwt-token-verifier
269	269-lossless-text-compressor	269 — Multi-Concept: Lossless Text Compressor (RLE & Frequency Coding)	269-lossless-text-compressor
270	270-json-patch-diff-engine	270 — Multi-Concept: JSON Patch & Diff Engine (RFC 6902 Sync)	270-json-patch-diff-engine
271	271-lru-lfu-cache-engine	271 — Multi-Concept: LRU/LFU Dual Cache Engine (Eviction Policies)	271-lru-lfu-cache-engine
272	272-crypto-hash-chain	272 — Multi-Concept: Cryptographic Hash Chain (Immutable Ledger)	272-crypto-hash-chain
273	273-micro-redux-store	273 — Capstone: Micro Redux Store (Unidirectional State & Reducers)	273-micro-redux-store
274	274-in-memory-sql-engine	274 — Capstone: In-Memory SQL Engine (SELECT, JOIN, GROUP BY)	274-in-memory-sql-engine
275	275-virtual-dom-reconciler	275 — Capstone: Virtual DOM Reconciler & Diff Tree (VDOM Engine)	275-virtual-dom-reconciler
276	276-dependency-injection-container	276 — Capstone: Dependency Injection Container (IoC & Lifecycles)	276-dependency-injection-container
277	277-full-reactive-kanban-engine	277 — Grand Capstone: Reactive Kanban State Engine (Full Production System)	277-full-reactive-kanban-engine

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🚀 Getting Started

git clone https://github.com/altradits/js-mastery.git
cd js-mastery
npm test