Luacheck module — luacheck 0.21.2 documentation

# Luacheck module

Use `local luacheck = require "luacheck"` to import `luacheck` module. It contains the following functions:

- `luacheck.get_report(source)`: Given source string, returns analysis data (a table).
- `luacheck.process_reports(reports, options)`: Processes array of analysis reports and applies options. `reports[i]` uses `options`, `options[i]`, `options[i][1]`, `options[i][2]`, ... as options, overriding each other in that order. Options table is a table with fields similar to config options; see Config options. Analysis reports with field `fatal` are ignored. `process_reports` returns final report, see Report format.
- `luacheck.check_strings(sources, options)`: Checks array of sources using options, returns final report. Tables with field `fatal` within `sources` array are ignored.
- `luacheck.check_files(files, options)`: Checks array of files using options, returns final report. Open file handles can passed instead of filenames, in which case they will be read till EOF and closed.
- `luacheck.get_message(issue)`: Returns a string message for an issue, see Report format.

`luacheck._VERSION` contains Luacheck version as a string in `MAJOR.MINOR.PATCH` format.

Using `luacheck` as a function is equivalent to calling `luacheck.check_files`.

## Report format

A final report is an array of file reports plus fields `warnings`, `errors` and `fatals` containing total number of warnings, errors and fatal errors, correspondingly.

A file report is an array of issues (warnings or errors). If a fatal error occurred while checking a file, its report will have `fatal` field containing error type and `msg` field containing error message.

An issue is a table with field `code` indicating its type (see List of warnings), and fields `line`, `column` and `end_column` pointing to the source of the warning. `name` field may contain name of related variable. Issues of some types can also have additional fields:

Codes | Additional fields
--- | ---
011 | `msg` field contains syntax error message.
111 | `module` field indicates that assignment is to a non-module global variable.
122, 142, 143 | `indirect` field indicates that the global field was accessed using a local alias.
122, 142, 143 | `field` field contains string representation of related global field.
211 | `func` field indicates that unused variable is a function.
211 | `recursive` field indicates that unused function is recursive.
211 | `mutually_recursive` field is set for unused mutually recursive functions.
314 | `field` field contains string representation of ununsed field or index.
4.. | `prev_line` and `prev_column` fields contain location of the overwritten definition.
521 | `label` field contains label name.
631 | `line_ending` field contains `"comment"` or `"string"` if line ending is within a comment or a string.
631 | `max_length` field contains maximum allowed line length.

Other fields may be present for internal reasons.