Kixx Templating

A simple and robust text templating system for JavaScript environments.

Principles

• No dependencies: A template engine is a low level primitive component which systems depend on and should NOT complicate matters by having dependencies itself.
• Minimal: The scope of supported capabilities is kept intentionally small.

Environment Support

| Env | Version | |---------|------------| | ECMA | >= ES2022 | | Node.js | >= 16.13.2 | | Deno | >= 1.0.0 |

Usage Documentation

See the docs/ folder for comprehensive docs.

Mustache Compatibility

Kixx targets the core Mustache spec where it fits the project's constraints and performance goals. The optional Mustache extensions ~lambdas, ~dynamic-names, and ~inheritance are intentionally unsupported. Use inline and block helpers for template logic that would otherwise be expressed with lambdas.

One intentional divergence: pure data sections iterate arrays, Maps, Sets, and plain object values. Core Mustache treats plain object sections as a single pushed context.

See mustache-conformance-report.md for a detailed report.

Architecture

Kixx Templating is a mustache-style templating engine with three public compilation steps:

1. Tokenize (lib/tokenize.js) - Splits template source into tokens, handles dynamic Mustache delimiters like {{=<% %>=}}, and captures standalone whitespace metadata.
2. Build Syntax Tree (lib/build-syntax-tree.js) - Parses tokens into an AST for content, comments, interpolations, sections, helpers, partials, delimiter changes, and raw output tags.
3. Create Render Function (lib/create-render-function.js) - Compiles the AST into pre-bound render closures. Rendering uses a zero-copy context stack for Mustache name resolution instead of copying context objects for nested scopes.

Development

The package.json defines the following commands:

| Command | Description | |---------|-------------| | npm run benchmark | Runs the Phase 8 performance benchmark suite and writes tmp/phase8-benchmark-report.md. | | npm run benchmark:quick | Runs a shorter smoke-test version of the Phase 8 benchmarks. | | npm test | Runs the full suite: the linter, the unit/snapshot tests, and the Mustache spec compliance gate. | | npm run spec | Runs only the Mustache spec compliance check. It compiles every test from the vendored spec (test/mustache-spec/) and compares the results against the checked-in baseline (test/mustache-spec-baseline.json). Read-only; exits non-zero if results regress or otherwise drift from the baseline. | | npm run spec:report | Runs the spec check and (re)generates the human-readable conformance report at tmp/mustache-conformance-report.md. | | npm run spec:update | Re-runs the spec suite and rewrites the baseline and report. Run this after intentionally changing rendering behavior to lock in the new expected outcomes. |

The Mustache spec suite is a conformance tracker: the baseline records the expected outcome (pass / fail / threw) of every spec test, tagged with the root cause of each failure, so npm test stays green while the engine is iteratively brought toward Mustache spec compliance.

Copyright and License

Copyright: (c) 2023 - 2026 by Kris Walker (www.kriswalker.me)

Unless otherwise indicated, all source code is licensed under the MIT license. See LICENSE for details.