SHARD-2733 updated linting setup and rules. Added rule for unused pure functions

[mssabr01]

PR Type

Enhancement

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Description

• Migrated ESLint configuration to flat config with eslint.config.mjs

• Added custom ESLint plugin for unused pure function calls

• Updated and expanded ESLint and related dependencies

• Improved lint script and dependency versions in package.json

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Changes walkthrough 📝

	Relevant files
Configuration changes	eslint.config.mjs Add flat ESLint config with custom rules and ignores          eslint.config.mjs Introduced new flat ESLint config using modern API Integrated TypeScript, security, and custom pure-functions plugin Replicated and enhanced ignore patterns from previous config Applied Prettier and security rules, and custom pure function rule +166/-0  .eslintrc.json Remove legacy ESLint configuration file                                    .eslintrc.json Removed legacy ESLint config in favor of flat config +0/-74
Enhancement	index.js Add custom ESLint plugin entry for pure functions                eslint-plugin-pure-functions/index.js Added entry point for custom ESLint plugin Registered new rule: no-unused-pure-calls Provided recommended config for plugin usage +15/-0    no-unused-pure-calls.js Add rule to detect unused pure function calls                        eslint-plugin-pure-functions/rules/no-unused-pure-calls.js Implemented ESLint rule to detect unused pure function calls Supports auto-fix and suggestions for assignment Configurable list of pure methods, with sensible defaults Provides detailed context-aware detection of unused results +173/-0
Dependencies	package.json Update ESLint dependencies and scripts for new config        package.json Updated ESLint and related dependencies to latest versions Added new dev dependencies for flat config and plugin support Improved lint script for quieter output Reordered and cleaned up dependency sections +14/-10

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[github-actions]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 4 🔵🔵🔵🔵⚪

🏅 Score: 88

🧪 No relevant tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Version Bump of @shardeum-foundation Packages The PR updates dependencies and devDependencies, but also includes unrelated changes to @shardeum-foundation packages. These should be in a separate PR or commit to avoid merge conflicts between branch lines with different versions. "@hapi/sntp": "3.1.1", "@mapbox/node-pre-gyp": "1.0.10", "@shardeum-foundation/lib-crypto-utils": "4.3.1", "@shardeum-foundation/lib-net": "1.6.1", "@shardeum-foundation/lib-types": "1.4.1", "@types/better-sqlite3": "7.6.3", "body-parser": "1.18.3", "bytenode": "1.3.4", "cors": "2.8.5", "deepmerge": "4.2.2", "express": "4.19.2", "got": "11.8.6", "log4js": "6.9.1", "log4js-extend": "0.2.1", "nat-api": "timadinorth/nat-api#appsec-dep-fix", "neverthrow": "6.0.0", "rfdc": "1.4.1", "socket.io": "2.5.0", "sqlite3": "5.1.6", "streamroller": "3.1.3", "tar-fs": "2.1.0", "trie-prefix-tree": "1.5.1" }, Rule Coverage and False Positives The custom ESLint rule for unused pure function calls uses a hardcoded list of method names and context checks. Reviewers should validate that the rule does not produce false positives or negatives, especially for edge cases or custom pure functions not in the list. const defaultPureMethods = [ // Array methods that return new arrays 'concat', 'slice', 'map', 'filter', 'reduce', 'reduceRight', 'find', 'findIndex', 'some', 'every', 'includes', 'indexOf', 'lastIndexOf', 'join', 'toString', 'toLocaleString', 'flatMap', 'flat', 'with', 'toReversed', 'toSorted', 'toSpliced', // String methods that return new strings 'substring', 'substr', 'toLowerCase', 'toUpperCase', 'trim', 'trimStart', 'trimEnd', 'replace', 'replaceAll', 'split', 'padStart', 'padEnd', 'repeat', 'charAt', 'charCodeAt', 'slice', 'substr', 'substring', // Object methods that return new objects/values 'assign', 'keys', 'values', 'entries', 'freeze', 'seal', 'getOwnPropertyNames', 'getOwnPropertyDescriptors', 'sign', ] const options = context.options[0] || {} const pureMethods = [...defaultPureMethods, ...(options.pureMethods || [])] function isPureMethodCall(node) { if (node.type !== 'CallExpression') return false if (node.callee.type !== 'MemberExpression') return false if (node.callee.property.type !== 'Identifier') return false return pureMethods.includes(node.callee.property.name) } Lint Ignore Patterns The ignore patterns in the ESLint config are extensive and may unintentionally exclude files that should be linted. Reviewers should confirm that all necessary files are still covered by linting. { ignores: [ '**/dist/**', '**/build/**', '**/node_modules/**', '**/*.js', '**/*.cjs', '**/*.mjs', // Specific files to ignore from the old config '**/shardus-types.ts', '**/Wrapper.ts', '**/Utils.ts', '**/Template.ts', '**/Sync.ts', '**/SafetyMode.ts', '**/Refresh.ts', '**/NodeList.ts', '**/Lost.ts', '**/GlobalAccounts.ts', '**/CycleCreator.ts', '**/CycleChain.ts', '**/CycleAutoScale.ts', '**/Context.ts', '**/Comms.ts', '**/Archivers.ts', '**/Apoptosis.ts', '**/Active.ts', '**/debugMiddleware.ts', '**/debug.ts', '**/config.test.ts', '**/computePowGenerator.ts', '**/storage/index.ts', '**/statistics/index.ts', '**/snapshot/index.ts', '**/shardus/index.ts', '**/reporter/index.ts', '**/rate-limiting/index.ts', '**/random/index.ts', '**/network/index.ts', '**/logger/index.ts', '**/load-detection/index.ts', '**/src/index.ts', '**/http/index.ts', '**/exit-handler/index.ts', '**/AccountPatcher.ts', '**/CachedAppDataManager.ts', '**/iterables.ts', '**/rotation.ts', '**/src/state-manager/PartitionStats.ts', '**/src/state-manager/index.ts', ], },

[github-actions]

Suggestion: The pureMethods array may contain duplicate method names, especially since some methods like 'slice', 'substr', and 'substring' appear multiple times in defaultPureMethods. This can cause unnecessary repeated checks and potential confusion. Remove duplicates from the pureMethods array to ensure each method is only checked once. [general, importance: 6]

Suggested change

	const pureMethods = [...defaultPureMethods, ...(options.pureMethods || [])]
	const pureMethods = Array.from(new Set([...defaultPureMethods, ...(options.pureMethods || [])]))

[github-actions]

Suggestion: The defaultPureMethods array includes 'assign', which is not a pure function (Object.assign mutates the first argument). Remove 'assign' to avoid false positives where mutating methods are flagged as pure. [possible issue, importance: 9]

Suggested change

	'assign',
	'keys',
	'values',
	'entries',
	'freeze',
	'seal',
	'getOwnPropertyNames',
	'getOwnPropertyDescriptors',
	'sign',
	]
	'keys',
	'values',
	'entries',
	'freeze',
	'seal',
	'getOwnPropertyNames',
	'getOwnPropertyDescriptors',
	'sign',
	]