Merge pull request liquity#708 from liquity/readme_coverage

Add coverage section to README

README.md

@@ -1,6 +1,6 @@
 # Liquity: Decentralized Borrowing Protocol
 
-![Tests](https://github.com/liquity/dev/workflows/CI/badge.svg) [![Frontend status](https://img.shields.io/uptimerobot/status/m784948796-056b56fd51c67d682c11bb24?label=Testnet&logo=nginx&logoColor=white)](https://devui.liquity.org) ![uptime](https://img.shields.io/uptimerobot/ratio/7/m784948796-056b56fd51c67d682c11bb24) [![Discord](https://img.shields.io/discord/700620821198143498?label=join%20chat&logo=discord&logoColor=white)](https://discord.gg/2up5U32) [![Docker Pulls](https://img.shields.io/docker/pulls/liquity/dev-frontend?label=dev-frontend%20pulls&logo=docker&logoColor=white)](https://hub.docker.com/r/liquity/dev-frontend)
+![Tests](https://github.com/liquity/dev/workflows/CI/badge.svg) [![Frontend status](https://img.shields.io/uptimerobot/status/m784948796-056b56fd51c67d682c11bb24?label=Testnet&logo=nginx&logoColor=white)](https://devui.liquity.org) ![uptime](https://img.shields.io/uptimerobot/ratio/7/m784948796-056b56fd51c67d682c11bb24) [![Discord](https://img.shields.io/discord/700620821198143498?label=join%20chat&logo=discord&logoColor=white)](https://discord.gg/2up5U32) [![Docker Pulls](https://img.shields.io/docker/pulls/liquity/dev-frontend?label=dev-frontend%20pulls&logo=docker&logoColor=white)](https://hub.docker.com/r/liquity/dev-frontend) [![codecov](https://codecov.io/gh/liquity/dev/branch/add_codecov/graph/badge.svg)](https://codecov.io/gh/liquity/dev)
 
 
 Liquity is a decentralized protocol that allows Ether holders to obtain maximum liquidity against
@@ -68,6 +68,7 @@ Visit [liquity.org](https://www.liquity.org) to find out more and join the discu
 - [Running Tests](#running-tests)
   - [Brownie Tests](#brownie-tests)
   - [OpenEthereum](#openethereum)
+  - [Coverage](#coverage)
 - [System Quantities - Units and Representation](#system-quantities---units-and-representation)
   - [Integer representations of decimals](#integer-representations-of-decimals)
 - [Public Data](#public-data)
@@ -690,6 +691,20 @@ To stop the Openethereum node, you can do it with:
 yarn stop-dev-chain
 ```
 
+### Coverage
+
+To check test coverage you can run:
+```
+yarn coverage
+```
+
+You can see the coverage status at mainnet deployment [here](https://codecov.io/gh/liquity/dev/tree/8f52f2906f99414c0b1c3a84c95c74c319b7a8c6).
+
+![Impacted file tree graph](https://codecov.io/gh/liquity/dev/pull/707/graphs/tree.svg?width=650&height=150&src=pr&token=7AJPQ3TW0O&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=liquity)
+
+There’s also a [pull request](https://github.com/liquity/dev/pull/515) to increase the coverage, but it hasn’t been merged yet because it modifies some smart contracts (mostly removing unnecessary checks).
+
+
 ## System Quantities - Units and Representation
 
 ### Integer representations of decimals