dosa

library1.0.0jsnpmunverified

Dosa is a JavaScript AST transpiler for instrumentation, wrapping variable accesses, function calls, binary expressions, and string literals with custom box_* functions. Version 1.0.0 is the initial stable release with no active development. It uses UglifyJS under the hood to parse and transform code, targeting debugging or runtime monitoring. Unlike Babel plugins or other instrumentation libraries, Dosa focuses on a simple, predictable transformation pattern, making it suitable for lightweight tracing but limited in customization.

observability devops

npm install dosa

github ↗package ↗

INSTALL

IMPORT

SIG · DOSA

dosa

observabilityjavascriptv1.0.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

dosa (default)

✓ import dosa from 'dosa'

✗ const dosa = require('dosa')

Package does not ship TypeScript types; use @types/dosa if available. Default export is a function with an `instrument` method.

instrument

✓ import { instrument } from 'dosa'

✗ const instrument = require('dosa').instrument

Named export available since v1.0.0.

DosaOptions

✓ import type { DosaOptions } from 'dosa'

✗ import { DosaOptions } from 'dosa'

Not available in v1.0.0; options are untyped. Use JSDoc for type safety.

Demonstrates basic usage: import the instrument function, pass JavaScript source code, get instrumented output with wrapped calls and string literals.

import { instrument } from 'dosa'; const input = "var a = location.hash.split('#')[1]"; const output = instrument(input); console.log(output); // 'var a = box_accessor(box_call(location.hash.split(box_string("#"))), 1);'

Debug

Known issues

gotchaInstrumentation wraps all function calls and property accesses, which can break performance and runtime behavior if not expected.

fix

Use only in development or debugging contexts; do not use in production without profiling.

affects: >=1.0.0

gotchaThe package does not handle dynamic eval() or with() statements; they will be passed through unchanged without instrumentation.

fix

Avoid using eval() or with() in source code to ensure consistent instrumentation.

affects: >=1.0.0

deprecatedNo longer maintained; last release 2018. Consider using @babel/plugin-transform-runtime or custom Babel plugin for more robust instrumentation.

fix

Migrate to a maintained alternative like babel-plugin-istanbul or a custom Babel plugin.

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'uglify-js'

Missing peer dependency uglify-js

fix

Run `npm install uglify-js` alongside dosa.

TypeError: dosa.instrument is not a function

Using require('dosa') which returns an object, not the instrument function directly

fix

Use `const dosa = require('dosa'); dosa.instrument(input);` or ES6 import.

Upgrade

Version history

1.0.0latest on npm

Audit

Dependencies

uglify-jsrequiredUsed for parsing and AST manipulation

Agent activity

18 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/skepticfx/dosa ↗

packagehttps://www.npmjs.com/package/dosa ↗