Also add config/jest/setupJest.js so we can configure jest-fetch-mock
Test plan: I have verified that mocked fetch works as expected in a
downstream commit.
Summary:
This removes the hard-coded route data from the Webpack config,
replacing it with the list of paths exported by the route data module.
Test Plan:
Note that the output of `yarn build` is identical before and after this
change: namely,
```shell
$ find build -exec shasum -a 256 {} + | shasum -a 256
7610a61f8a977f1d8edd849fc81256ca15f41f366e5fdb4b59a5d5ce37d6d58e
```
wchargin-branch: non-hard-coded-route-data
Summary:
Some of the code here is adapted from my site (source available on
GitHub at wchargin/wchargin.github.io). It has been improved when
possible and made worse when necessary to fit into our existing build
system with minimal churn.
As of this commit, there remain the following outstanding tasks:
- Use a non-hardcoded list of paths in static site generation router.
This is not trivial. We have the paths nicely available in
`routes.js`, but this module is written in ES6, and transitively
depends on many files written in ES6 (i.e., the whole app). Yet
naïvely it would be required from a Webpack config file, which is
interpreted as vanilla JavaScript.
- Add `csso-loader` to minify our CSS. This is easy.
- Add unit tests for `dedent`. (As is, it comes from my site
verbatim. I wrote it. dmnd’s `dedent` package on npm is insufficient
because it dedents arguments as well as the format string, which is
incorrect at least for our purposes.)
- Link in canonical static data for the site.
- Rip out the whole build system and replace it with my build config,
which is orders of magnitude saner and less bad. (By “the whole
build system” I mostly mean `webpack.config.{dev,prod}.js`.)
Test Plan:
```shell
$ yarn backend
$ yarn build
$ node ./bin/sourcecred.js start
```
wchargin-branch: static-v0
Test plan:
`git grep -i v3` only shows incidental hits in longer strings
`yarn travis --full` passes
`yarn backend` works
`yarn build` works
`yarn start` works
`node bin/sourcecred.js start` works
`node bin/sourcecred.js load sourcecred example-github` works
Paired with @wchargin
Summary:
The bridge introduced in #448 has now served its purpose, and may be
deconstructed. This implements the first part of the last step of the
plan described in that pull request.
Paired with @decentralion.
Test Plan:
After `yarn backend && yarn build`:
- `node bin/sourcecred.js start` works, and
- `yarn start` works, and
- `yarn travis --full` works.
wchargin-branch: demolish-bridge
Test plan:
`node bin/sourcecred.js load sourcecred example-github` works
`yarn start` works
`node bin/sourcecred.js start-v3` works
`yarn travis --full` passes
Paired with @wchargin
Summary:
This could also be moved into the bridge directory, but this way is
marginally easier, and it doesn’t really matter in the end.
Test Plan:
`yarn backend` followed by `node bin/sourcecredV3.js start-v3` works.
wchargin-branch: start-v3
The `load` command replaces `plugin-load`. By default, it loads data for
all plugins, and does so in parallel using execDependencyGraph. If
passed the optional `--plugin` flag, then it will load data just for
that plugin.
As an implementation detail, when loading all plugins, load calls itself
with the plugin flag set.
Usage:
`node bin/sourcecred.js load repoOwner repoName`
Test plan:
Tested by hand; I blew away my SourceCred directory and then loaded the
example-github repository.
Summary:
Our build system doesn’t make it easy to have two separate React
applications, which we would like to have for the V1 and V3 branches.
Instead, we’ll implement a bridge to maintain compatibility.
The plan looks like this:
1. Change the app from pointing to V1 to pointing to a bridge
2. Move the router into the bridge and move the V1 app from the `/`
route to the `/v1` route (e.g., `/v1/explorer`)
3. Add a V3 app under the `/v3` route
4. ???
5. Delete the V1 app and remove it from the bridge
6. Delete the bridge and move the V3 app from the `/v3` route to `/`
This commit implements Step 1.
Test Plan:
To verify that the bridge is in fact showing, apply
```diff
diff --git a/src/bridge/app/index.js b/src/bridge/app/index.js
index 379e289..72e784c 100644
--- a/src/bridge/app/index.js
+++ b/src/bridge/app/index.js
@@ -9,5 +9,11 @@ const root = document.getElementById("root");
if (root == null) {
throw new Error("Unable to find root element!");
}
-ReactDOM.render(<V1App />, root);
+ReactDOM.render(
+ <React.Fragment>
+ <h1>Hello</h1>
+ <V1App />
+ </React.Fragment>,
+ root
+);
registerServiceWorker();
```
and say “hello” back to the app.
wchargin-branch: bridge
Summary:
This provides a command-line entry point `load-plugin-v3` (which will
become `load-plugin` eventually), which fetches the GitHub data via
GraphQL and saves the resulting `RelationalStore` to disk.
A change to the Babel config is needed to prevent runtime errors of the
form `_callee7` is not defined, where `_callee7` is a gensym that is
appears exactly once in the source (in use position, not definition
position). I’m not sure exactly what is causing the error or why this
config change fixes it. But while this patch may be fragile, I don’t
think that it’s likely to subtly break anything, so I’m okay with
pushing it for now and dealing with any resulting breakage as it arises.
Paired with @decentralion.
Test Plan:
Run `yarn backend`, then run something like:
```
node bin/sourcecredV3.js load-plugin-v3 \
sourcecred example-github --plugin github
```
Inspect results in `SOURCECRED_DIR/data/OWNER/NAME/github/view.json`,
where `SOURCECRED_DIR` is `/tmp/sourcecred` by default, and `OWNER` and
`NAME` are the repository owner and name.
This example repository takes about 1.1 seconds to run. The SourceCred
repository takes about 45 seconds.
wchargin-branch: cli-load-plugin
Summary:
Due to oclif’s structure, this entry point shares its `commands`
directory with that of the V1 entry point. We’ll therefore add commands
like `start-v3` as we go.
Test Plan:
`yarn backend` works, and `node bin/sourcecredV3.js start` launches the
V1 server.
wchargin-branch: v3-cli
Summary:
Many files are unchanged. Some files have had paths updated, or new
build/test targets added.
The `types.js` file includes payload type definitions. These are
technically independent of the graph abstraction (i.e., nothing from V1
is imported and the code all still works), but it of course implicitly
depends on the V1 model. For now, we include the entirety of this file,
just so that we have a clean copy operation. Subsequent commits will
strip out this extraneous code.
Suggest reviewing with the `--find-copies-harder` argument to Git’s
diffing functions.
Test Plan:
Running `yarn travis --full` passes. Running
./src/v3/plugins/git/demoData/synchronizeToGithub.sh --dry-run
yields “Everything up-to-date”.
wchargin-branch: git-v3-copy
This commit copies the following logic necessary for downloading GitHub
data into v3. Minimal changes have been made to accomodate the new path
structure.
Test plan:
- Manually ran plugins/github/fetchGithubRepoTest.sh and verified that
it can correctly pass and fail
- Added the v3 github repo test to `yarn travis --full`
- Ran `yarn travis --full` and it passed
Paired with @wchargin
We want to reset some of our basic assumptions, and make `Graph` into a
pure graph implementation, rather than a hybrid graph and key-value
store.
This is a substantial rewrite, so we want to start from scratch in a v3/
directory and pull code into v3 as necessary. So that we can do this in
a relatively clean fashion, we're first moving the v1 and v2 code into
their own directories.
Paired with @wchargin
Test plan: Travis, and `yarn backend`, `node bin/sourcecred.js start`.
Note that `yarn backend` and `node bin/sourcecred.js start` both use the
v1 versions. We'll migrate those (by changing paths.js) to v3 when
appropriate.
Summary:
This fixes a bug introduced in #317, which only occurred in the cron job
variant of the CI script (`yarn travis --full`): the two scripts run in
the cron job depend on `yarn backend` having previously written to the
`bin/` directory, but this is precisely what we wanted to prevent. To
fix this, we simply add an additional target for `yarn backend` during
the cron job. This is a little bit wasteful in that we compile the
backend applications twice, but it’s not a big deal because (a) it only
runs in cron jobs, so it won’t slow down normal builds, and (b) it only
takes about 5 seconds, anyway.
Test Plan:
Export a `GITHUB_TOKEN` and run `yarn travis --full`, which fails before
this change and passes after it.
wchargin-branch: cron-ci-overwrite-bin
Summary:
Previously, our CI script would run `yarn backend`, which has the
side-effect of erasing the `bin/` directory. By itself, this is not
great, but not awful. However, this frequently triggers a race condition
in Prettier, causing the `check-pretty` step of the build to fail. (More
details: https://github.com/prettier/prettier/issues/4468.)
This patch changes the CI script to build the backend scripts into a
temporary directory.
Test Plan:
Before applying this patch: `yarn backend` and then `yarn travis`. If
this consistently causes a Travis failure due to `check-pretty`, then
your machine can reproduce the race condition that we‛re trying to
eliminate. (Otherwise, you can try creating a bunch more Git history…
I’m not really sure what to say. It is a race condition, after all.)
Then, apply this patch, and repeat the above steps; note that the error
no longer occurs, and that the build output is to a temporary directory.
wchargin-branch: ci-preserve-bin
As of this commit, adding the comment `//$ExpectFlowError` in flow-typed
code asserts that the next line must cause a flow error. If it does, no
error or warning is generated. If it does not, then this produces a flow
warning, which is visible to developers running `yarn flow` and
additionally causes travis to fail.
Test plan:
- As committed, `yarn travis` passes.
- I added `//$ExpectFlowError` above some line of flow-checked code which does
not currently throw an error. Afterwards, `yarn travis` failed (and a
helpful message was displayed in console on running `yarn flow`)
- I added the following bad code into one of our files:
```javascript
//$ExpectFlowError
const foo: string = 3;
```
As expected, `yarn flow` and `yarn travis` both passed.
Test Plan:
Run `yarn flow stop; yarn travis | cat` and note the absence of the
really long line that has ~2500 bytes of “Server is initializing”.
wchargin-branch: quiet-flow-server
Summary:
Placing `STOPSHIP` or `stopship` (or any case variant) in any file
tracked by Git will now cause a `yarn travis` failure. If you need to
use this string, you can concatenate it as `"stop" + "ship"` or
equivalent.
Test Plan:
In `travis.js`, change `"check-stop" + "ships"` to `"check-stopships"`,
and note that this causes the build to fail with a nice message. Note
that this also causes `check-stopships.sh` to fail even when invoked
from an unrelated directory, like `src`.
wchargin-branch: check-stopships
Summary:
A few changes were made to code that is correct (as far as I can tell),
but for which Flow can no longer infer a type parameter. The change is a
bit more annoying than it otherwise would be, because this particular
file is run directly via node and so must use Flow’s comment syntax for
type annotations, but Prettier breaks such comments in the cases that we
need. We work around this by rewriting the original code to avoid the
need for comments.
Test Plan:
In addition to standard CI, run `yarn build` and then run a server from
`build/`, to see that the production build produces a working bundle.
(That the app loads and renders is sufficient.)
wchargin-branch: upgrade-flow-v0.72.0
Summary:
This way, our frontend can talk to a backend that can read from the
filesystem (among other things).
Paired with @decentralion.
Test Plan:
```
$ yarn backend
$ SOURCECRED_DIRECTORY=/tmp/srccrd yarn start
$ # verify that the browser looks good
$ mkdir /tmp/srccrd
$ echo hello >/tmp/srccrd/world
$ curl localhost:3000/api/v1/data/world
hello
$ curl localhost:4000/api/v1/data/world
hello
```
wchargin-branch: webpack-proxy
It was doing some clever array construction that added possible booleans
to the array, then filtered them out. To make the typing simpler for
Flow's inspection, we now only put string elements in the array.
Test plan: `yarn travis --full` passed, and the CLI still works.
- scripts/backend.js: We incorrectly set an environment variable to
a boolean, when in fact it must be a string. Fixed it to set a string
value "true", and updated usage in config/babel.js
- scripts/test.js: No changes
- scripts/build.js: Removed a call to printHostingInstructions, so that
we don't need to require the package.json.
Test plan:
`yarn travis --full` passes, and the SourceCred cli still works.
- Fix accidental string-to-NaN coercion in ensureSlash
- Don't dynamically require package.json; to determine public url, just
use the environment variable or "/"
Test plan: `yarn start` and travis still work
This commit executes a micro-refactor to move all top-level app setup
code out of src/plugins/artifact/editor and into src/app. The observed
behavior from `yarn start`, which is to show the artifact editor, is
unchanged.
Summary:
We need a way for our web applications to interact with data on the
filesystem. In this commit, we introduce a webserver that serves
statically from two directory trees: first, the result of a live-updated
Webpack build; second, the SourceCred data directory.
Test Plan:
Run `yarn backend` and `node ./bin/sourcecred.js start`. When ready,
navigate to the server’s root route in a web browser. Note that a nice
React app is displayed. Then, change something in that React app source.
Note that the server console displays Webpack’s update messages, and
that refreshing the page in the browser renders the new version of the
app. Finally, visit
/__data__/graphs/sourcecred/example-github/graph.json
in the browser to see the graph for the example repository, assuming
that you had generated its graph previously.
wchargin-branch: start
This script ensures that either //@flow or //@no-flow is present in
every js file. Every existing js file that would fail this check has
been given //@no-flow, we should work to remove all of these in the
future.
Test plan:
I verified that `yarn travis` fails before fixing the other js files,
and passes afterwards.
Our SourceCred CLI tool now ipmlements printCombinedGraph and
cloneAndPrintGitGraph, but with more principled implementations and
interfaces :)
Test plan:
`yarn travis --full` passes, so I didn't delete any needed test infra.
Summary:
This commit implements the `sourcecred` command-line utility, which has
three subcommands:
- `plugin-graph` creates one plugin’s graph;
- `combine` combines multiple on-disk graphs; and
- `graph` creates all plugins’ graphs and combines them.
As an implementation detail, the `into.sh` script is very convenient,
avoiding needing to do any pipe management in Node (which is Not Fun).
When we build for release, we may want to factor that differently.
Test Plan:
To see it all in action, run `yarn backend`, and then try:
```
$ export SOURCECRED_GITHUB_TOKEN="your_token_here"
$ node ./bin/sourcecred.js graph sourcecred sourcecred
Using output directory: /tmp/sourcecred/sourcecred
Starting tasks
GO create-git
GO create-github
PASS create-github
PASS create-git
GO combine
PASS combine
Full results
PASS create-git
PASS create-github
PASS combine
Overview
Final result: SUCCESS
$ ls /tmp/sourcecred/sourcecred/
graph-github.json graph-git.json graph.json
$ jq '.nodes | length' /tmp/sourcecred/sourcecred/*.json
1000
7302
8302
```
The `node sourcecred.js graph` command takes 9.8s for me.
(The salient point of the last command is that the two small graphs have
node count adding up to the node count of the big graph. Incidentally,
we are [almost][1] at a nice round number of nodes in the GitHub graph.)
[1]: https://xkcd.com/1000/
wchargin-branch: cli
Summary:
To be honest, I have no idea what exactly this does or why it’s
necessary, but if we don’t do this then it is not possible to `import`
the exported member from a Webpack-bundled script. I’ve seen this
pattern before; one day I’ll actually figure out what it does. :-)
Test Plan:
Note that `yarn travis` (success) and `yarn travis --full` (failure; no
GitHub token) both have the expected behaviors.
wchargin-branch: execdependencygraph-export
This commit adds [oclif] as a command-line framework. It is successfully
integrated with webpack.
[oclif]: https://github.com/oclif/oclif
Usage:
`yarn backend` to build the cli.
`node bin/sourcecred.js` to launch the CLI and see usage
`node bin/sourcecred.js example` for one example command
`node bin/sourcecred.js goodbye` for another example command
Summary:
Consequently, Babel won’t transform classes to their roughly equivalent
ES5 counterparts, etc.
Test Plan:
Create `src/classy.js` with `class X {}; console.log(X);`. Then, add a
build target for `classy: resolveApp("src/classy.js"),` in `paths.js`.
Use `yarn backend` and inspect the contents of `bin/classy.js`; in
particular, look at the definition of `X` (whatever the argument to
`console.log` is). Before this commit, the result will be a big
complicated mess. After this commit, it will be `class X {}`.
Note also that `yarn travis --full` passes, indicating that the two
manual tests, which call out to the utilities in `bin/`, still work.
wchargin-branch: target-node
Summary:
We want to change this configuration so that our compilation of backend
applications can target latest Node. This commit forks the current
configuration so that we can modify it easily.
Test Plan:
Both `yarn start` and `yarn travis` work. The generated backend
applications work, too.
wchargin-branch: fork-babel-config
Setup following directions from [webpack-node-externals]
[webpack-node-externals]: https://www.npmjs.com/package/webpack-node-externals
This unblocks #210.
Test plan: `yarn backend` still succeeds, and the binary scripts still
work. The resultant binaries are much smaller, as seen below (note build
time is the same).
before:
```
❯ yarn backend
yarn run v1.5.1
$ node scripts/backend.js
Building backend applications...
Compiled successfully.
File sizes after gzip:
231.37 KB bin/printCombinedGraph.js
199.5 KB bin/fetchAndPrintGithubRepo.js
46.41 KB bin/cloneAndPrintGitGraph.js
21.48 KB bin/createExampleRepo.js
17.71 KB bin/loadAndPrintGitRepository.js
Build completed; results in 'bin'.
Done in 4.46s.
```
after:
```
❯ yarn backend
yarn run v1.5.1
$ node scripts/backend.js
Building backend applications...
Compiled successfully.
File sizes after gzip:
27.78 KB bin/printCombinedGraph.js
12.73 KB bin/cloneAndPrintGitGraph.js
12.41 KB bin/fetchAndPrintGithubRepo.js
6.03 KB bin/loadAndPrintGitRepository.js
5.52 KB bin/createExampleRepo.js
Build completed; results in 'bin'.
Done in 4.28s.
```
Summary:
We’d like to use the same abstraction for creating multiple cred graphs
and then combining them together. This will enable us to do that.
Test Plan:
Run `yarn travis` to test the success case, and `yarn travis --full`
(without setting a `GITHUB_TOKEN`) to test the failure case.
wchargin-branch: execdepgraph
`printCombinedGraph` loads and prints a cross-plugin combined
contribution graph for a given GitHub repository.
It is a simple executable wrapper around `src/tools/loadCombinedGraph`.
Example usage:
`node bin/printCombinedGraph.js sourcecred example-git $GITHUB_TOKEN`
`cloneAndPrintGitGraph` clones a git repository, and generates a Git
object graph for that repository.
This can be run as follows:
```
yarn backend;
node bin/cloneAndPrintGitGraph sourcecred example-git
```
This commit also adds two utility modules:
* `cloneAndLoadRepository` , which clones a Git repository to a tmpdir,
parses the `Repository` data out, and then cleans up.
* `cloneGitGraph`, which calls `cloneAndLoadRepository` and `createGraph`
Test plan: These don't fit well into our CI, because they require
network access to clone repositories from GitHub. I verified that the
functions work via the demo script above.
Summary:
This could catch failures in build configuration or with Webpack. It’s
unlikely to catch any logic errors, because no production code is run.
In any case, it’s fast enough; it finishes at about the same time as
`ci-test` and `check-pretty`.
Test Plan:
From the repository root, run `rm -r bin; yarn travis`, and note that
the `bin/` directory is regenerated.
wchargin-branch: ci-backend
Summary:
This prevents the boilerplate output of the form
```
> sourcecred-explorer@0.1.0 check-pretty /home/wchargin/git/sourcecred
> prettier --list-different '**/*.js'
```
(superfluous linebreaks included). In the case that a script fails, it
also omits the giant “this is most likely not a problem with npm” block.
The downside to this is that it suppresses any errors in npm-run-script
itself. For instance, `npm run wat` produces “missing script: wat”,
while `npm run --silent wat` just silently exits with 1. This does not
silence the actual scripts themselves, so things like lint errors or
test failures will still appear.
Test Plan:
Run `yarn travis` before and after this commit, and note that the
resulting build log is prettier after.
wchargin-branch: ci-silent
Summary:
This CI script accomplishes two tasks:
1. It speeds up our build by parallelizing where possible.
2. It opens the possibility for running Travis cron jobs.
Currently, this script by default does the same amount of work as our
current CI script. However, I’d like to move `yarn backend` into the
list of basic actions: a backend build failure should fail CI.
Note: this script is written to be executable directly by Node, so we
can’t use Flow types with the standard syntax. Instead, we use the
comment syntax: https://flow.org/en/docs/types/comments/
Test Plan:
The following should pass with useful output:
- `npm run travis`
- `GITHUB_TOKEN="your_github_token" npm run travis -- --full`
The following should fail with useful output:
- `npm run travis -- --full` (fail)
To test different failure modes, it can be helpful to add
```js
{id: "doomed", cmd: ["false"], deps: []},
{id: "orphan", cmd: ["whoami"], deps: ["who", "are", "you"]},
```
to the list of `basicTasks` in `travis.js`.
To test performance:
```shell
$ time node ./config/travis.js >/dev/null 2>/dev/null
real 0m8.306s
user 0m20.336s
sys 0m1.364s
$ time bash -c \
> 'npm run check-pretty && npm run lint && npm run flow && CI=1 npm run test' \
> >/dev/null 2>/dev/null
real 0m12.427s
user 0m13.752s
sys 0m0.804s
```
A 50% savings is not bad at all—and the raw time saved should only
improve from here on, as the individual steps start taking more time.
wchargin-branch: custom-ci
Test Plan:
Run `yarn lint` and `yarn travis` and observe success. Add something
that triggers a lint warning, like `const zzz = 3;`; re-run and observe
failures.
wchargin-branch: lint
Summary:
Two reasons for this. First, we want tests to be able to operate on this
data without having to generate repositories via `git(1)`. (Doing that
is slow, and requires a Git installation, and makes it less clear that
the tests are correctly isolated/provides more surface area for
something to go wrong.) Second, in general plugins will need a canonical
source of test data, so setting/continuing this precedent is a good
thing.
Test Plan:
Observe that the old Jest snapshot must be equivalent to the new JSON
one, because the test criterion in `loadRepository.test.js` changed and
the test still passes. Then, run `loadRepositoryTest.sh` and note that
it passes; change the `example-git.json` file and note that the test
fails when re-run; then, run the test with `--updateSnapshot` and watch
it magically revert your changes.
wchargin-branch: check-in-git-repo
Summary:
We’ll use this to create the repositories on disk and then push them to
GitHub.
Test Plan:
Generate both kinds of repository, and check out the SHAs:
```shell
$ yarn backend
$ node bin/createExampleRepo.js /tmp/repo
$ node bin/createExampleRepo.js --submodule /tmp/repo-submodule
$ node bin/createExampleRepo.js --no-submodule /tmp/repo-no-submodule
$ # (first and third lines do the same thing)
$ git -C /tmp/repo rev-parse HEAD
677b340674bde17fdaac3b5f5eef929139ef2a52
$ git -C /tmp/repo-submodule rev-parse HEAD
29ef158bc982733e2ba429fcf73e2f7562244188
$ git -C /tmp/repo-no-submodule rev-parse HEAD
677b340674bde17fdaac3b5f5eef929139ef2a52
```
Then, note that these SHAs are expected per the snapshot file in
`exampleRepo.test.js.snap`.
wchargin-branch: create-example-repo-command
* Make GitHub capitalization consistent within code
We now never capitalize the H in GitHub within variable or function
names. We still capitalize it in comments or user facing strings.
Test plan:
Unit tests, the fetchGithubRepoTest.sh, and
`git grep itHub` only shows comment lines and print statements.
* Fix William's klaxon
Summary:
We’ll now start creating the artifact plugin. A large part of this will
be the user interface, including a GUI. For now, our build system just
builds a single React app, so we’re cannibalizing the main explorer to
serve this purpose.
Paired with @dandelionmane.
Test Plan:
The following still work:
- `yarn test`
- `yarn start`
- `yarn build; (cd build; python -m SimpleHTTPServer)`
wchargin-branch: repurpose-react-app-as-artifact-editor
Summary:
Running `yarn backend` will now bundle backend applications. They’ll be
placed into the new `bin/` directory. This enables us to use ES6 modules
with the standard syntax, Flow types, and all the other goodies that
we’ve come to expect. A backend build takes about 2.5s on my laptop.
Created by forking the prod configuration to a backend configuration and
trimming it down appropriately.
To test out the new changes, this commit changes `fetchGitHubRepo` and
its driver to use the ES6 module system and Flow types, both of which
are properly resolved.
Test Plan:
Run `yarn backend`. Then, you can directly run an entry point via
```
$ node bin/fetchAndPrintGitHubRepo.js sourcecred example-repo "${TOKEN}"
```
or invoke the standard test driver via
```shell
$ GITHUB_TOKEN="${TOKEN}" src/backend/fetchGitHubRepoTest.sh
```
where `${TOKEN}` is your GitHub authentication token.
wchargin-branch: webpack-backend
Reorganize the code so that we have a single package.json file, which is at the root.
All source code now lives under `src`, separated into `src/backend` and `src/explorer`.
Test plan:
- run `yarn start` - it works
- run `yarn test` - it finds the tests (all in src/explorer) and they pass
- run `yarn flow` - it works. (tested with an error, that works too)
- run `yarn prettify` - it finds all the js files and writes to them
Dandelion Mané
William Chargin
Dandelion Mané