Commit Graph

798 Commits

Author SHA1 Message Date
William Chargin bdb9ae9c46
Demonstrate the GitHub token env var in the README (#556)
Summary:
Using the environment variable is the preferred way to interact with the
CLI, simply because it’s easier for users. We should demonstrate this
interface instead of the legacy flag-only version.

Paired with @decentralion.

wchargin-branch: readme-env-var
2018-07-27 20:59:54 -07:00
William Chargin 68fa7237a0
Add external link to Discord invite (#551)
Test Plan:
None really needed—the infrastructure has already been tested—but you
can verify that this works both under `yarn start` and `yarn build` by
navigating to the evident URL.

wchargin-branch: discord-invite
2018-07-27 20:18:22 -07:00
William Chargin 8e062592ae
Add external redirect infrastructure (#550)
Summary:
This patch extends our routing infrastructure to add support for
_external_ redirects. It does not include dedicated support for
site-internal redirects.

Test Plan:
Add an external redirect to `routeData`, like the following:

```diff
diff --git a/src/app/routeData.js b/src/app/routeData.js
index 83dff72..eaba130 100644
--- a/src/app/routeData.js
+++ b/src/app/routeData.js
@@ -36,6 +36,15 @@ const routeData /*: $ReadOnlyArray<RouteDatum> */ = [
     title: "SourceCred explorer",
     navTitle: "Explorer",
   },
+  {
+    path: "/discord-invite",
+    contents: {
+      type: "EXTERNAL_REDIRECT",
+      redirectTo: "https://discord.gg/tsBTgc9",
+    },
+    title: "SourceCred Discord invite",
+    navTitle: null,
+  },
 ];
 exports.routeData = routeData;

```

Then:
  - run `yarn build`, and:
     - verify that the appropriate `index.html` file is correctly
       generated;
     - verify that opening the `index.html` file in a browser redirects
       you to the appropriate destination, even with JavaScript
       disabled;
     - verify that the link in the body of the HTML page is correct
       (easier to do if you remove the `<meta>` tag)
  - run `yarn start`, and:
    1. use the React DevTools to change the “Explorer” link’s `to` prop
       from `/explorer` to `/discord-invite`;
    2. click the link; and
    3. verify that you are properly redirected.

wchargin-branch: add-external-redirect
2018-07-27 19:13:51 -07:00
William Chargin 24a950629a
Add all available flow-typed libdefs (#548)
Summary:
Generated with `flow-typed install --skip --overwrite`.

Test Plan:
Amazingly, `yarn flow` passes. Go team.

wchargin-branch: add-libdefs
2018-07-27 17:23:24 -07:00
Dandelion Mané 49da7cfdb0
Display cred explorer scores as -Log(score) (#535)
@wchargin suggested displaying scores this way. This way, lowest scores
are best, and higher scores are worse. This is a little
counterintuitive, but maybe less counterintuitive than the current
approach, which arbitrarily adds 10 to scores to keep them non-negative,
and results in an arbitrary crossing point where scores become negative
without any particular significance.

Test plan: Travis, and manual inspection of the frontend.
2018-07-27 17:04:29 -07:00
William Chargin 873eca6350
Upgrade Flow to v0.76.0 (#546)
Summary:
In addition to a routine libdef update, we also need to work around a
particularly nasty new bug in Flow, which requires `any`-casts that are
even more unsafe than usual. That said, I think that it’s worth that
cost to remain up to date with Flow, so that we can amortize future such
issues.

Test Plan:
Running `yarn travis --full` passes.

wchargin-branch: upgrade-flow-v0.76.0
2018-07-27 15:54:59 -07:00
Dandelion Mané e669e89315
RepositorySelect displays NO_REPOS on 404 (#547)
Test plan: Unit tests included, plus I manually tested it.
2018-07-27 15:47:15 -07:00
Dandelion Mané 0b0815eb12
When repo registry fails, error to console (#544)
Some slight changes were needed to the other test code to avoid spurious
errors. Specifically, we now always set up a mocked fetch response in
non-failure cases, even if we don't wait for it to resolve.

Test plan: I manually tested it, also see the new unit tests.
2018-07-27 15:42:18 -07:00
Dandelion Mané 126fdb69dc
Add default weights for node types (#543)
Modifies the PluginAdapter interface so that NodeTypes come with
default weights, and modify the WeightConfig so that it loads those
NodeTypes as the default weights.

The new weight choices are not super principled, but are clearly better
than the uniform default. Now, projects find that most pull requests are
more valuable than most git blobs. :)

Sadly, the WeightConfig does not yet have any tests, so there are no
test changes.

Test plan: I manually verified that it works as expected, by clearing
application data and reloading the cred explorer.
2018-07-27 15:34:11 -07:00
Dandelion Mané 294616b556
RepositorySelect tests verify no console errors (#545)
We should really do this as a matter of course on all frontend testing.
Not sure what the right pattern is for ensuring that.

Test plan: Travis
2018-07-27 15:32:47 -07:00
Dandelion Mané ec5b76a83d
Upgrade oclif packages to latest (#542)
This required adding a [files property] to the package.json,
otherwise oclif started complaining.

Test plan: I manually tested both CLI commands, and they seem fine.

[files property]: https://docs.npmjs.com/files/package.json#files
2018-07-27 14:32:30 -07:00
Dandelion Mané b61b8fbdb8
Improve error messages when GitHub query fails (#536)
Currently, the GitHub graph fetcher will characteristically fail if:
1. it times out GitHub's server
2. it triggers the semidocumented abuse detection mechanism

In case 1, an intelligible error is posted to the console. In case 2, it
produces an unintelligible TypeError, because the response is not a
valid GraphQL response (the error field is not populated; it has a
custom message instead).

As of this commit, we gracefully catch both cases, and print a message
to console directing the user to #350, which has context on GitHub query
failures. This new catch works because in case 2, the data field is
empty, so we now properly recognize `x.data === undefined` as an error
case.

Thanks to @wchargin for the investigatory work behind this commit.

Fixes #223.

Test plan:
We don't have unit tests that cover this case, but I did manually test
it by asking GitHub to fetch `ipfs/go-ipfs`, which consistently fails.
I also tested it by using an invalid length-40 GitHub API token.
2018-07-27 13:27:40 -07:00
Dandelion Mané deaba09d00
Upgrade react and react-dom to latest (#541)
Test plan: `yarn travis --full`, as well as thorough manual frontend
testing
2018-07-27 13:27:19 -07:00
Dandelion Mané 28a31cfcd6
Reorganize dependencies and devDependencies (#540)
This commit is a good faith effort to separate our dependencies (code
that SourceCred app or CLI require to run) from devDependencies (all
other deps) in our package.json.

We don't have any actual dependents, so it's hard to test this
distinction. Hence, it's a good faith effort.

Test plan:
`rm -r node_modules && yarn && yarn travis` works.
2018-07-27 12:38:40 -07:00
William Chargin 4058a3fd85
Extract `dedent` to `util`, adding tests (#538)
Summary:
There have been a couple of occasions on which we’ve considered using
it, but didn’t want to require from `app/`.

Test Plan:
Unit tests added, with full coverage.

wchargin-branch: extract-dedent
2018-07-27 12:30:28 -07:00
Dandelion Mané 6b13ab64a0
Remove unused tensorflowjs dependency (#539)
Test plan: Travis
2018-07-27 12:29:04 -07:00
Dandelion Mané 797fb6331d
Upgrade jest to 23.4.1 (#537)
Flow types regenerated via flow-typed install jest@23.4.1

Test plan: Travis
2018-07-27 12:28:04 -07:00
Dandelion Mané aa3382a8b2
Default to selecting last loaded repository (#531)
In #529, I made the cred explorer populate a dropdown with the list of
repositories that are available to explore. That dropdown defaults to
selecting the alphabetically first repository.

This has an unfortunate consequence in that it makes it impossible for
us to explicitly set a default - for example, we would like
sourcecred.github.io/explorer to show sourcecred/sourcecred by default,
but instead it shows example-git.

So that we can choose the default, I've changed the logic so that it
instead shows the most-recently-loaded data first. This required
a breaking change to the repoRegistry serialized format, so I've also
refactored the module to use compat, which I should have done from the
beginning.

Test plan:
Unit tests for the repo selector are updated. The CLI load command
unfortunately has no tests, so I manually tested that it always provides
the lastest repository last, and appropriately handles the case where
the same repository is loaded multiple times.
2018-07-27 10:33:15 -07:00
Dandelion Mané e845e8cbbc
Modify sourcecred.github.io's example repos (#533)
Showing our example-github and example-git repos on sourcecred.github.io
is not particularly interesting. Let's show ipfs/js-ipfs instead!

Since sourcecred/sourcecred is the last repo to load, as of #531 it will
be the default option.

Test plan: Dry run of deploy script
2018-07-26 21:57:43 -07:00
Dandelion Mané a0c07bf0d7
Import the sourcecred.github.io deploy script (#532)
This copies the deploy script from sourcecred/sourcecred.github.io into
the sourcecred/sourcecred repository. It's been modified to reflect the
fact that it is no longer run from within the sourcecred.github.io
repository.

We’re moving this script into the main SourceCred repository so that it
can be versioned in the same tree as everything else, and in particular
so that the hash-of-built-commit depends on the build script itself.

The script was originally created by @wchargin in
https://github.com/sourcecred/sourcecred.github.io/pull/1 at hash
e8bc5b669b31df34b439b194cb62af4fd9a789d8, subsequently modified in
https://github.com/sourcecred/sourcecred.github.io/pull/2 and
https://github.com/sourcecred/sourcecred.github.io/pull/3 and
https://github.com/sourcecred/sourcecred.github.io/pull/4

Paired with @wchargin

Test plan: Ran locally (on dry-run) and inspected output.
2018-07-26 21:05:18 -07:00
Dandelion Mané f110114833
Convert Explorer repository selection to dropdown (#529)
Context: The Cred Explorer loads data (currently on a per-repository
basis) that has previously been prepared by running the `sourcecred
load` cli command.

Currently, to select a repository to load, the user must manually type
the repository owner and name. This is a confusing UI, because it
suggests that any repository may be chosen, when in fact only repos
already loaded into the data store are available. The user is given no
feedback as to which repositories are valid options.

As of #516, the backend stores a registry listing available
repositories. This commit adds a `RepositorySelect` component which
loads the available from that registry, and makes them available in a
dropdown, in sorted order.

When the user manually selects one of the repositories, that selection
is persisted into localStorage and respected on future loads. If the
user hasn't made such a choice, then the first repository is selected by
default.

The implementation is highly influenced by testability considerations.
The default export, `<RepositorySelect onChange={} localStore={} />`, is
pretty straightforward. The `RepositorySelect` is somewhat cumbersome to
test because it asynchronously fetches data and then updates its state,
which affects the render output. So as to avoid testing inside async
react components wherever possible, I've factored out:

* `loadStatus`, which uses fetch and localStore to get the status of the
selector.
* `PureRepositorySelect`, which just renders a `Status`, such as
loading, failure, or valid
* `LocalStoreRepositorySelect`, which wraps the `PureRepositorySelect`
with logic to bind the repository select to localStore on change.

Test plan: Extensive unit tests were added. Also, to ensure that the
tests were testing the right thing, I manually tested:
- attempting to load invalid registry
- attempting to load with no registry
- attempting to load with empty registry
- loading without valid localStore
- changing the setting via dropdown
- loading from localStore after changing the dropdown

And all behavior was as expected.

Thanks to @wchargin for considerable help testing this PR.
2018-07-26 19:24:25 -07:00
Dandelion Mané e36a7c1af2
Fix a mistake in the implementation of #527 (#530)
Test plan: Travis
2018-07-26 18:32:34 -07:00
Dandelion Mané e06b88364e
Add jest-fetch-mock as dev dependency (#528)
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.
2018-07-26 15:08:14 -07:00
William Chargin e0c97fee9e
Extract a `TestLocalStore` (#527)
Summary:
Test code should probably always use a checked, memory-backed local
storage implementation. This endpoint will help users not forget to
include the checks.

wchargin-branch: test-local-store
2018-07-26 15:05:43 -07:00
William Chargin 8655838b2c
Use `CheckedLocalStore` in the cred explorer (#526)
Summary:
Might as well have runtime type safety, in case we accidentally try to
store any more `Map`s or `undefined`s.

Test Plan:
Tests pass, but are likely not sufficient. Manual testing indicates that
the local storage still works, for both reads and writes, on a fresh
profile or with existing data, for both the repository owner/name and
the weight configuration.

wchargin-branch: use-checked-local-store
2018-07-24 19:34:35 -07:00
William Chargin c0da12af6e
Use `MemoryLocalStore` for existing tests (#525)
Summary:
This resolves a TODO. It’s not urgent, but it’s good practice.

wchargin-branch: use-memory-local-store
2018-07-24 19:19:53 -07:00
William Chargin 0489ff8844
Add a `memoryLocalStore` implementation (#524)
Summary:
We can use this in tests. If need be, we can enhance this class to allow
simulating failures, low storage limits, etc., but just having a pure
implementation at all is all we need right now.

Test Plan:
Unit tests added.

wchargin-branch: memory-local-store
2018-07-24 19:10:38 -07:00
William Chargin d0906eed16
Add a `checkedLocalStore` implementation (#523)
Summary:
This provides some extra checking around `LocalStore` calls. In
particular, it fails fast on the nasty bug where storing a `Map`
actually stores the empty object (`JSON.stringify(new Map()) === "{}"`).
Similarly, retrieving a value that was stored as `undefined` will raise
an error, because `JSON.parse(JSON.stringify(undefined))` raises an
error.

This should have negligible performance impact—local storage access
should never be on a critical path. We can choose to elide this in
production if we want.

Test Plan:
Unit tests added. Manual testing of the cred explorer yields no errors.

wchargin-branch: checked-local-store
2018-07-24 19:00:39 -07:00
William Chargin 801b4ec700
Dependency-inject `LocalStore` (#522)
Summary:
This commit modifies components that directly depend on the
browser-specific local store implementation to instead have their
dependencies injected.

Test Plan:
Tests pass, but are likely not sufficient. Manual testing indicates that
the local storage still works, for both reads and writes, on a fresh
profile or with existing data, for both the repository owner/name and
the weight configuration.

wchargin-branch: di-localstore
2018-07-24 18:56:36 -07:00
William Chargin 1fa039ba6c
Extract a `LocalStore` interface (#521)
Summary:
We’d really like to be able to test components that use `LocalStore`. We
can do this by dependency-injecting the storage backend. This commit
begins that process by extracting `LocalStore` to its interface,
preserving the unique existing implementation.

wchargin-branch: extract-localstore
2018-07-24 18:53:40 -07:00
William Chargin 77fa29320c
Reduce memory pressure by double-buffered PageRank (#520)
Summary:
This commit switches to a double-buffered PageRank implementation. When
benchmarked on `ipfs/js-ipfs`, the critical section improves from
3059 ms to 2433 ms (79.5% of original), and peak heap usage drops from
342 MB to 207 MB. (Tested non-rigorously in Chrome 67.)

Test Plan:
Existing unit tests for `sparseMarkovChainAction`,
`findStationaryDistribution`, and `pagerank` are sufficient.

wchargin-branch: pagerank-dbuf
2018-07-24 17:51:40 -07:00
William Chargin 4435a3cfad
Make PageRank functions asynchronous (#519)
Summary:
The PageRank functions can take a long time to compute. We’d like them
to not lock the browser, and we’d also like them to communicate with
their clients (e.g., to update a progress bar). This code updates
`findStationaryDistribution` and downstream `pagerank` to return
promises.

Test Plan:
Unit tests updated. The cred explorer (`yarn start`) still works.
Applying

```diff
diff --git a/src/core/attribution/markovChain.js b/src/core/attribution/markovChain.js
index 2acce9c..c7a7159 100644
--- a/src/core/attribution/markovChain.js
+++ b/src/core/attribution/markovChain.js
@@ -166,6 +166,7 @@ export function findStationaryDistribution(
           return;
         }
       } while (Date.now() - start < yieldAfterMs);
+      console.log("Yielding.");
       setTimeout(tick, 0);
     };
     tick();
```

causes the appropriate log messages to be printed in the browser—about
once every ten iterations for `sourcecred/sourcecred`.

wchargin-branch: asynchronous-pagerank
2018-07-24 17:46:32 -07:00
Claire L 854fd817c0
README: Adding contribution section (#518)
* README: Adding contribution section

* README: adding links to Prettier
2018-07-24 13:38:40 -07:00
Dandelion Mané cd6c869d84
Add a registry of loaded repositories (#516)
We want the UI to offer a list of available repositories, rather than
using a text input box. To do this, we first need the backend to include
a registry of all available repositories.

Test plan:
Sadly we don't have CLI testing, so I manually verified this by doing
the following:

```
$ yarn backend
$ rm -r $SOURCECRED_DIRECTORY
$ node bin/sourcecred.js load sourcecred example-github
$ cat $SOURCECRED_DIRECTORY/repositoryRegistry.json
{"sourcecred/example-github":true}
$ node bin/sourcecred.js load sourcecred example-github
$ cat $SOURCECRED_DIRECTORY/repositoryRegistry.json
{"sourcecred/example-github":true}
$ node bin/sourcecred.js load sourcecred example-git
$ cat $SOURCECRED_DIRECTORY/repositoryRegistry.json
{"sourcecred/example-git":true,"sourcecred/example-github":true}
```
2018-07-24 12:33:58 -07:00
Dandelion Mané 94a023ef6f
WeightConfig loads from plugin adapters (#515)
Previously, WeightConfig hackily contained its own enumeration of all
node and edge types. Now, it loads them from the StaticPluginAdapter.

Test plan:
Unit tests pass, as does manual inspection of the frontend.
2018-07-23 15:40:43 -07:00
Dandelion Mané 2a39844445
Split PluginAdapter into Dynamic and Static parts (#513)
In some cases (e.g. WeightConfig) we want to have information from the
PluginAdapater before loading any data from the server. In other cases,
we need to combine the PluginAdapater with actual data, e.g. so we can
get the description of a GitHub node.

To support this, we split the PluginAdapter into a Static and Dynamic
component. The Dynamic component has data needed to give node
descriptions, etc. Given a static adapter, you can get a promise to load
the dynamic adapter. Given the dynamic adapter, you can immediately get
the static adapter. (There's a parallel to NodeReference (static) and
NodePorcelain (dynamic)).

Test plan:
Travis passes, as does manual testing of the frontend.
2018-07-23 15:37:14 -07:00
Dandelion Mané 3c14ef8a43
Refactor PluginAdapter abstraction (#512)
- PluginAdapters no longer expose a Renderer; instead, the render
methods are inlined on the PluginAdapter. The extra abstraction didn't
provide any lift in the current architecture.

- The edgeVerb function has been removed.

- PluginAdapters now enumerate EdgeTypes. Each has a prefix, and a
forward and a backward name.

Test plan: `yarn travis`, plus manual testing of the frontend and the
weight config.
2018-07-23 15:25:17 -07:00
William Chargin 28100275c4
Disable service workers (#514)
Summary:
We don’t need this to be a “progressive web app”—certainly not now. The
n+1 caching problem is not a good tradeoff for us, and furthermore
service workers are causing flashes of content on server-side rendered
pages.

This commit is a quick fix to remove them. We can remove the code
entirely if we want, or just keep it as is.

Test Plan:
On a machine has the service worker registered, run `yarn build`, then
`node bin/sourcecred.js start`. Note in the network panel that the
service worker is loaded on the first page load, but then deregistered.
On subsequent refreshes, it should not activate. In the “Application”
panel of the Chrome dev tools, it should appear as “deleted”.

wchargin-branch: disable-sw
2018-07-23 15:16:45 -07:00
Dandelion Mané 943d04cc70
Allow expanding/hiding the WeightConfig (#511)
The WeightConfig is a power user feature. Now that we're building a
public-facing demo out of the Cred Explorer, it will be better to hide
the weight configuration by default.

This commit adds a button for showing/hiding the weight configuration.
The weights are still propagated correctly regardless of whether the
weight config is shown.

Test plan:
- Ensure that the site loads with weights hidden by default.
- Ensure that clicking the button causes the weight config to display.
- Ensure that PageRank loads and displays correctly with the weights
hidden.
- Ensure that changes to the weight config still propagate to PageRank
(with weights hidden or not hidden).
2018-07-23 14:05:06 -07:00
William Chargin 9a356f88a1 Use route data for static site source of truth
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
2018-07-23 13:29:48 -07:00
William Chargin 73e36b2ab2 Make route path data available in vanilla context
Test Plan:
Ensure that `require("./src/app/routeData")` works in `node` without any
preprocessing. Ensure that `yarn start` works, and that `yarn build`
then `node ./bin/sourcecred.js start` also works.

wchargin-branch: vanilla-route-data
2018-07-23 13:29:48 -07:00
William Chargin b41009b1f7 Implement a first-pass static site generation
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
2018-07-23 13:29:48 -07:00
William Chargin df76975fae Add static-site-generator-webpack-plugin
wchargin-branch: add-ssgwp
2018-07-23 13:29:48 -07:00
William Chargin 08e8494170 Update page title on route change
Test Plan:
Navigate to `/`, then click the “Explorer” link, and note that the page
title has updated.

wchargin-branch: update-page-title
2018-07-23 13:29:48 -07:00
William Chargin 256582d8b3 Add a landing page
Summary:
This adds a dummy landing page. We’ll want to actually put nice content
on it. For development convenience, I’m totally fine with having the
`yarn start` launch `/explorer` instead of just `/`.

Test Plan:
Run `yarn start` and note that the navigation works.

wchargin-branch: landing-page
2018-07-23 13:29:48 -07:00
William Chargin 6be05e91c8 Add basic react-router@3 routing
Summary:
This commit introduces a `Page` component that we can use to provide
common styling and navigation to our pages.

wchargin-branch: use-rrv3
2018-07-23 13:29:48 -07:00
William Chargin 04acce4a4c Remove dependency on react-router-dom
Test Plan:
Note that nothing breaks, because we don’t actually have any routing
right now.

wchargin-branch: remove-rrv4
2018-07-23 13:29:48 -07:00
William Chargin 767a64bbe7 Add dependency on react-router^3.2.1
Summary:
We’re switching from RRv4 to RRv3. We’ll remove RRv4, which is currently
unused, in the next commit.

wchargin-branch: add-rrv3
2018-07-23 13:29:48 -07:00
William Chargin ab0fa81a40
Show PageRank node decomposition in the explorer (#507)
Summary:
This commit hooks up the PageRank table to the PageRank node
decomposition developed previously. The new cred explorer displays one
entry per contribution to a node’s cred (i.e., one entry per in-edge,
per out-edge, and per synthetic loop), listing the proportion of the
node’s cred that is provided by this contribution. This makes it easy to
observe facts like, “90% of this issue’s cred is due to being written by
a particular author”.

Paired with @decentralion.

Test Plan:
Unit tests added; run `yarn travis`.

wchargin-branch: pagerank-table-node-decomposition
2018-07-23 10:42:40 -07:00
William Chargin bb7b538f44
Use `NullUtil` functions where appropriate (#506)
Summary:
The aesthetically nicest win is in `WeightConfig`. Other changes are
nice to have.

In many cases, we reduce the specificity of error messages thrown. For
instance, if an invariant was violated on an edge `e`, then we might
have thrown an error with message `EdgeAddress.toString(e.address)`. But
we did so not because we thought that this was genuinely worth it, but
only because we were forced to explicitly throw an error at all. These
errors should never be hit, anyway, so we don’t feel bad about replacing
these with errors that are simply the string `"null"` or `"undefined"`,
as appropriate.

Test Plan:
Running `yarn travis --full` passes, and the cred explorer still seems
to work with both populated and empty `localStorage`.

wchargin-branch: use-null-util
2018-07-09 17:53:05 -07:00