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https://github.com/AdamNiederer/cov

An emacs extension for displaying coverage data on your code
https://github.com/AdamNiederer/cov

clover coverage coverage-data coveralls emacs gcov lcov profiling

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An emacs extension for displaying coverage data on your code

Lists

README 

        
![GPLv3](https://img.shields.io/badge/license-GPLv3-brightgreen.svg)

[![Build Status](https://travis-ci.org/AdamNiederer/cov.svg?branch=master)](https://travis-ci.org/AdamNiederer/cov)

[![MELPA](http://melpa.org/packages/cov-badge.svg)](http://melpa.org/#/cov)



[`gcov`]: https://gcc.gnu.org/onlinedocs/gcc/Gcov.html

 "gcov — a Test Coverage Program"

[`lcov`]: https://github.com/linux-test-project/lcov

 "lcov — a graphical frontend for gcov"

[`coverage.py`]: https://coverage.readthedocs.io

 "Coverage.py is a tool for measuring code coverage of Python programs."

[`clover`]: https://openclover.org

 "OpenClover — Java, Groovy and AspectJ code coverage tool"

[`Coveralls`]: https://coveralls.io

 "Coveralls — Test Coverage History & Statistics"

[`undercover.el`]: https://github.com/sviridov/undercover.el

 "undercover.el: A test coverage library for Emacs"

[MELPA]: https://melpa.org/#/cov "cov @ MELPA"



# cov



`cov` shows code coverage data for your program in emacs. Currently,

it supports [`gcov`], [`lcov`], [`coverage.py`], and [`clover`]

output, as well as the [`Coveralls`] format produced by

[`undercover.el`].



![Screenshot](example.png)



## Installation

`cov` is on [MELPA]. To install it, type `M-x package-install RET cov RET`



## Usage

Enable `cov-mode` in a buffer. It will use the methods in

`cov-coverage-file-paths` to look for a suitable coverage data file.

`cov-mode` uses file watchers to automatically reload the coverage

file when it has been updated.



Line coverage is displayed in the left fringe and added to the

`help-echo` text property of the line.



## Customization



### Profiling mode



By default, `cov` will run in profiling mode. Lines which are executed

a lot will have the fringe decorated with `cov-heavy-face`, while

lines executed less will have the fringe decorated with `cov-med-face`

and `cov-light-face`. Lines not executed at all will be decorated with

`cov-none-face`.



Use the `cov-high-threshold` and `cov-med-threshold` variables to

customize where the limits between haevy, medium, and light execution

should be.



### Coverage mode



Setting `cov-coverage-mode` to `t` *before enabling `cov-mode`* will

run cov in coverage mode. In this mode lines will be marked with

`cov-coverage-run-face` or `cov-coverage-not-run-face` to executed and

non-executed lines respectively. Coverage mode should make finding

uncovered lines slightly easier than profiling mode.



### Finding The Coverage File



Coverage files are located using the methods in

`cov-coverage-file-paths`, a list of paths or functions that are tried

in order to find a matching coverage file for the current buffer.



Paths can be used for coverage files which have the same name as the

source file but with a suffix added, like `gcov`.  So far `gcov` is

the only supported tool that uses this scheme, but more can be added

by appending to `cov-coverage-alist`.  `cov-coverage-alist` bind

postfixes to the coverage tools:



```lisp

(setq cov-coverage-alist '((".gcov" . gcov)))

```

For other tool or more complex environments it is also possible to provide a

function instead of a path string. The function will be called with

the path and name of the buffer file and should return a cons cell of

the form `(COV-FILE-PATH . COVERAGE-TOOL)`. `PATH` shall be the full path

and name of the coverage data file. `COVERAGE-TOOL` shall specify the

coverage tool.



#### Finding gcov Files



`gcov` files are located using `cov-coverage-file-paths` as described

above.



#### Finding lcov Files



An `lcov` tracefile can contain data for multiple source files and can

be named anything. There are two ways to find tracefiles.



1. Set `cov-lcov-file-name` to the absolute path of the tracefile.

   This can be done with a directory- or file-local variable.



2. Add pattarns or functions to `cov-lcov-patterns`.

   Relative or absolute file patterns like "../lcov.info" will be

   tested in order to find a matching file. Functions takes the dir

   and name of the source file as arguments and should return an

   absolute path.



#### Finding coveralls Files



Coveralls file are named `coverage-final.json` and are searched for in

each directory from the source file to the root.



#### Finding clover Files



Clover file are named `clover.xml` and are searched for in

each directory from the source file to the root.



#### Finding coverage.py Files



`coverage.py` file are named `coverage.json` and are searched for in

each directory from the source file to the root.



## Develop



`cov.el` can be extended to understand more coverage formats. To add

a new format:



1. Add a function to `cov-coverage-file-paths` that locates a coverage

   file for a given file. If a coverage file is found, it should

   return a cons of the coverage file path and an identifier, like

   `(cons filepath 'mytool)`. The original name of the file can be

   found in the `cov-coverage-file` buffer local variable.

2. Implement a `cov--mytool-parse`. The parse function is called with

   a temp buffer with the coverage file data as `(current-buffer)` and

   should parse the data and return the coverage as a alist of files

   to coverage mapping. Coverage data is simply a list of two element

   lists, where the first element is the line number and the second

   the coverage count.



### Test

Install dependencies:

```bash

cask install

```



Run tests:

```bash

cask exec ert-runner

```



## License

GPLv3+