4af8ff2471
Summary:
This commit adds a module with four functions: `get`, `orThrow`, `map`,
and `orElse`.
Here is a common pattern wherein `get` is useful:
```js
sortBy(Array.from(map.keys()), (x) => {
const result = map.get(x);
if (result == null) {
throw new Error("Cannot happen");
}
return result.score;
});
// versus
sortBy(Array.from(map.keys()), (x) => NullUtil.get(map.get(x)).score)
```
(The variant `orThrow` allows specifying a custom message that is only
computed in the case where the error will be thrown.)
Here is a common pattern where `map` is useful:
```js
arr.map((x) => {
const result = complicatedComputation(x);
return result == null ? result : processResult(result);
});
// versus
arr.map((x) => NullUtil.map(complicatedComputation(x), processResult))
```
In each of these cases, by using these functions we gain a dose of
safety in addition to our concision: it is tempting to “shorten” the
expression `x == null ? y : z` to simply `x ? y : z`, while forgetting
that the latter behaves incorrectly for `0`, `false`, `""`, and `NaN`.
Similar patterns like `x || defaultValue` also suffer from this problem,
and can now be replaced with `orElse`.
Designed with @decentralion.
Test Plan:
Unit tests included; run `yarn travis`.
wchargin-branch: null-util
SourceCred
Vision
Open source software is amazing, and so are its creators and maintainers. How amazing? It's difficult to tell, since we don't have good tools for recognizing those people. Many amazing open-source contributors labor in the shadows, going unappreciated for the work they do.
SourceCred will empower projects to track contributions and create cred, a reputational measure of how valuable each contribution was to the project. Algorithmically, contributions will be organized into a graph, with edges representing connections between contributions. Then, a configurable PageRank algorithm will distill that graph into a cred attribution.
SourceCred is dogfooding itself. People who contributes to SourceCred—by writing bug reports, participating in design discussions, or writing pull requests—will receive cred in SourceCred.
Design Goals
SourceCred development is organized around the following high-level goals.
- Transparent
It should be easy to see why cred is attributed as it is, and link a person's cred directly to contributions they've made.
- Community Controlled
Each community has the final say on what that community's cred is. We don't expect an algorithm to know what's best, so we'll empower communities to use algorithmic results as a starting point, and improve results with their knowledge.
- Decentralized
Individual projects and communities will control their own SourceCred instances, and own their own data. The SourceCred creators won't have the power to control or modify other projects' cred.
- Forkable
Forking is important to open source, and gives people the freedom to vote with their feet. SourceCred will support forking, and forks will be able to modify their cred independently of the original.
- Flexible & Extensible
SourceCred is focused on open-source projects for now, but we think it can be a general system for building reputation networks. We're organizing around very flexible core abstractions, and a plugin architecture for specific domains.
Current Status
As of July 2018, it's still early days for SourceCred! So far, we've set the following foundations:
- the graph class is the heart of SourceCred, and we've spent a lot of time polishing those APIs 🙂
- the GitHub plugin downloads data from GitHub and imports it into a graph
- the Git plugin clones a Git repository and imports it into a graph
- our PageRank implementation does cred attribution on the graph
- the cred explorer makes the PageRank results transparent
The PageRank results aren't very good yet - we need to add more configurability to get higher quality results. We're working out improvements in this issue.
Roadmap
The team is focused right now on building an end-to-end beta that can import GitHub repositories and produce a reasonable and configurable cred attribution. We hope to have the beta ready by November 2018.
Running the Prototype
If you'd like to try it out, you can run a local copy of SourceCred using the following commands. You need to have node and yarn installed first. You also need to get a GitHub API access token.
git clone https://github.com/sourcecred/sourcecred.git
cd sourcecred
yarn install
yarn backend
node bin/sourcecred.js load REPO_OWNER REPO_NAME --github-token=GH_TOKEN
yarn start
# then navigate to localhost:3000 in your browser
Getting Involved
If you'd like to help out, or you just think SourceCred seems cool and you want to learn more, please drop by our our Discord chat.