MLE-24763 Lint: Preferring const

[rjrudin]

Zillion little changes, but any issues should cause test failures locally and on Jenkins.

Copilot used auto-fix for these changes. There are 55 more issues to be fixed that require human judgment. Those will be dealt with later.

[github-actions]

Copyright Validation Results
Total: 28 | Passed: 27 | Failed: 0 | Skipped: 1 | at: 2025-10-17 14:09:17 UTC | commit: 746bc77

⏭️ Skipped (Excluded) Files

• lib/www-authenticate-patched/md5.js

✅ Valid Files

• eslint.config.js
• lib/documents.js
• lib/extlibs.js
• lib/graphs.js
• lib/internal.js
• lib/marklogic.js
• lib/mllog.js
• lib/mlutil.js
• lib/operation.js
• lib/optional.js
• lib/patch-builder.js
• lib/plan-builder-base.js
• lib/query-builder.js
• lib/requester.js
• lib/resources-config.js
• lib/resources-exec.js
• lib/responder.js
• lib/rest-server-properties.js
• lib/rows.js
• lib/server-exec.js
• lib/transactions.js
• lib/transforms.js
• lib/values-builder.js
• lib/values.js
• lib/www-authenticate-patched/parsers.js
• lib/www-authenticate-patched/user-credentials.js
• lib/www-authenticate-patched/www-authenticate.js

✅ All files have valid copyright headers!

[Copilot]

Pull Request Overview

This PR introduces linting enforcement for modern JavaScript (ES6+) and refactors many variable declarations from var to const or let across the codebase to align with the new rules.

• Adds ESLint rules prefer-const and no-var (both as errors).
• Refactors numerous files replacing var with const/let; adds semicolons and minor stylistic braces.
• No functional logic changes intended; primarily modernization for consistency with new lint standards.

Reviewed Changes

Copilot reviewed 28 out of 28 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
lib/www-authenticate-patched/www-authenticate.js	Replaces var with const/let; adds braces and semicolons for clarity.
lib/www-authenticate-patched/user-credentials.js	Modernizes variable declarations to const/let.
lib/www-authenticate-patched/parsers.js	Updates var to const/let in parsing logic.
lib/www-authenticate-patched/md5.js	Uses const for crypto import.
lib/values.js	Converts var to const/let across read logic.
lib/values-builder.js	Modernizes builder helper variables.
lib/transforms.js	Replaces var with const/let in transform operations.
lib/transactions.js	Updates transaction handling with const/let.
lib/server-exec.js	Refactors execution logic variable declarations; minor property access change.
lib/rows.js	Changes var to const/let in row query and streaming functions.
lib/rest-server-properties.js	Modernizes variable declarations.
lib/responder.js	Large refactor replacing var with const/let; adds braces and gzip handling with updated syntax.
lib/resources-exec.js	Updates request construction to const/let.
lib/resources-config.js	Modernizes resource config code.
lib/requester.js	Refactors request orchestration using const/let.
lib/query-builder.js	Extensive var-to-const/let refactor across query construction utilities.
lib/plan-builder-base.js	Adjusts loop counters and temp variables to const/let.
lib/patch-builder.js	Modernizes patch operation helpers.
lib/optional.js	Updates helper to use const.
lib/operation.js	Refactors internals with const/let.
lib/mlutil.js	Modernizes utilities (asArray, copyProperties, etc.).
lib/mllog.js	Uses const for util import.
lib/marklogic.js	Broad refactor of client setup to const/let.
lib/internal.js	Minor update (let→const) in request options.
lib/graphs.js	Modernizes graph handling functions.
lib/extlibs.js	Uses const/let for extension library management.
lib/documents.js	Large refactor adopting const/let throughout document CRUD and batch operations.
eslint.config.js	Adds prefer-const and no-var lint rules (error level).

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[Copilot]

Adding prefer-const as an error will cause lint failures because this PR leaves numerous let declarations that are never reassigned (e.g., server-exec.js line 247 source is not reassigned). Either convert such let usages to const in this PR or temporarily set prefer-const to 'warn' to avoid blocking builds.

Suggested change

	"prefer-const": "error", // Use const for variables never reassigned
	"prefer-const": "warn", // Use const for variables never reassigned (temporarily set to warn to avoid blocking builds)

[Copilot]

source is assigned once and never reassigned; with prefer-const enforced, change let to const to satisfy the new lint rule and improve immutability.