This commit adds support for [TC39 Decorator
Proposal](https://github.com/tc39/proposal-decorators).
These decorators are only available in transpiled sources - ie.
non-JavaScript files (because of lack of support in V8).
This entails that "experimental TypeScript decorators" are not available
by default
and require to be configured, with a configuration like this:
```
{
"compilerOptions": {
"experimentalDecorators": true
}
}
```
Closes https://github.com/denoland/deno/issues/19160
---------
Signed-off-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Co-authored-by: crowlkats <crowlkats@toaxl.com>
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>
This change sets the removal version for the `deno bundle` sub-command
for Deno v2. The warnings appear when `deno bundle` is run and in the
`--help` menu.
This initially uses the new diagnostic printer in `deno lint`,
`deno doc` and `deno publish`. In the limit we should also update
`deno check` to use this printer.
This commit removes the requirement for `--unstable` flag in `deno
jupyter` subcommand. The process will no longer exit if this flag is not
provided, however the subcommand itself is still considered unstable
and might change in the future.
Required for https://github.com/denoland/deno/pull/21452
This commit removes conditional type-checking of unstable APIs.
Before this commit `deno check` (or any other type-checking command and
the LSP) would error out if there was an unstable API in the code, but not
`--unstable` flag provided.
This situation hinders DX and makes it harder to configure Deno. Failing
during runtime unless `--unstable` flag is provided is enough in this case.
We were calling `expand_glob` on our excludes, which is very expensive
and unnecessary because we can pattern match while traversing instead.
1. Doesn't expand "exclude" globs. Instead pattern matches while walking
the directory.
2. Splits up the "include" into base paths and applicable file patterns.
This causes less pattern matching to occur because we're only pattern
matching on patterns that might match and not ones in completely
unrelated directories.
Main change is that:
- "hyper" has been renamed to "hyper_v014" to signal that it's legacy
- "hyper1" has been renamed to "hyper" and should be the default
Adds an `--unstable-sloppy-imports` flag which supports the
following for `file:` specifiers:
* Allows writing `./mod` in a specifier to do extension probing.
- ex. `import { Example } from "./example"` instead of `import { Example
} from "./example.ts"`
* Allows writing `./routes` to do directory extension probing for files
like `./routes/index.ts`
* Allows writing `./mod.js` for *mod.ts* files.
This functionality is **NOT RECOMMENDED** for general use with Deno:
1. It's not as optimal for perf:
https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-2/
1. It makes tooling in the ecosystem more complex in order to have to
understand this.
1. The "Deno way" is to be explicit about what you're doing. It's better
in the long run.
1. It doesn't work if published to the Deno registry because doing stuff
like extension probing with remote specifiers would be incredibly slow.
This is instead only recommended to help with migrating existing
projects to Deno. For example, it's very useful for getting CJS projects
written with import/export declaration working in Deno without modifying
module specifiers and for supporting TS ESM projects written with
`./mod.js` specifiers.
This feature will output warnings to guide the user towards correcting
their specifiers. Additionally, quick fixes are provided in the LSP to
update these specifiers:
A bit hacky, but it works. Essentially, this will check for all the
scripts in the node_modules/.bin directory then force them to run with
Deno via deno_task_shell.
This PR causes Deno to include more files in the graph based on how a
template literal looks that's provided to a dynamic import:
```ts
const file = await import(`./dir/${expr}`);
```
In this case, it will search the `dir` directory and descendant
directories for any .js/jsx/etc modules and include them in the graph.
To opt out of this behaviour, move the template literal to a separate
line:
```ts
const specifier = `./dir/${expr}`
const file = await import(specifier);
```
The self-upgrade feature is undesirable when deno is installed from
(Linux) distribution repository - using a system package manager. This
change will allow package maintainers to build deno with the "upgrade"
subcommand and background check disabled.
When the user runs `deno upgrade <args>` and the upgrade feature is
disabled, it will exit with error message explaining that this deno
binary was built without the upgrade feature.
Note: This patch is already used in the Alpine Linux’s
[deno](https://pkgs.alpinelinux.org/packages?name=deno) package.
This also updates deno_graph, which has the JSR change to use "exports".
It's not yet useful atm, so I've made this PR a fix about the deno doc
--lint error message improvements. I'll do a follow-up PR that adds
exports to the deno.json
This commit moves all Chrome Devtools Protocol messages to `cli/cdp.rs`
and refactors all places using these types to pull them from a common
place.
No functional changes.
As pointed out in https://github.com/denoland/deno/issues/21067 , it's
confusing that `deno doc --lint mod.ts` outputs the documentation to
stdout on success. Instead, it would be better if it outputted how many
files were checked similar to what `deno lint` does on success. It still
outputs the documentation if `--lint` or `--html` are provided so this
is non-breaking.
Adds a new `--lint` flag to `deno doc` that surfaces three kinds of
diagnostics:
1. Diagnostic for non-exported type referenced in an exported type.
* Why? People often forget to export types from a module in TypeScript.
To supress this diagnostic, add an `@internal` jsdoc tag to the internal
type.
1. Diagnostic for missing return type or missing property type on a
**public** type.
* Why? Otherwise `deno doc` will not display good documentation. Adding
explicit types also helps with type checking performance.
1. Diagnostic for missing jsdoc on a **public** type.
* Why? Everything should be documented. This diagnostic can be supressed
by adding a jsdoc comment description.
If the lint passes, `deno doc` generates documentation as usual.
For example, checking for deno doc diagnostics on the CI:
```shellsession
$ deno doc --lint mod.ts second_entrypoint.ts > /dev/null
```
This feature is incredibly useful for library authors.
## Why not include this in `deno lint`?
1. The command needs the documenation output in order to figure out the
diagnostics.
1. `deno lint` doesn't understand where the entrypoints are. That's
critical for the diagnostics to be useful.
1. It's much more performant to do this while generating documentation.
1. There is precedence in rustdoc (ex. `#![warn(missing_docs)]`).
## Why not `--check`?
It is confusing with `deno run --check`, since that means to run type
checking (and confusing with `deno check --docs`).
## Output Future Improvement
The output is not ideal atm, but it's fine for a first pass. We will
improve it in the future.
Closes https://github.com/denoland/deno_lint/pull/972
Closes https://github.com/denoland/deno_lint/issues/970
Closes https://github.com/denoland/deno/issues/19356
This commit adds `--unstable-hmr` flag, that enabled Hot Module Replacement.
This flag works like `--watch` and accepts the same arguments. If
HMR is not possible the process will be restarted instead.
Currently HMR is only supported in `deno run` subcommand.
Upon HMR a `CustomEvent("hmr")` will be dispatched that contains
information which file was changed in its `details` property.
---------
Co-authored-by: Valentin Anger <syrupthinker@gryphno.de>
Co-authored-by: David Sherret <dsherret@gmail.com>
This commit adds support for multiple entry points to `deno doc`.
Unfortunately to achieve that, I had to change the semantics of the
command to explicitly require `--filter` parameter for filtering
symbols, instead of treating second free argument as the filter argument.
`deno doc --builtin` is still supported, but cannot be mixed with
actual entrypoints.
Upgrades to deno_doc 0.70 which includes the feature for showing
non-exported types referenced in exported types as well as a much more
advanced deno doc that uses a symbol graph.
As title. This will help use the two independently from the other, which
will help in an upcoming deno doc PR where I need to parse the source
files with scope analysis.
This PR adds a new unstable "bring your own node_modules" (BYONM)
functionality currently behind a `--unstable-byonm` flag (`"unstable":
["byonm"]` in a deno.json).
This enables users to run a separate install command (ex. `npm install`,
`pnpm install`) then run `deno run main.ts` and Deno will respect the
layout of the node_modules directory as setup by the separate install
command. It also works with npm/yarn/pnpm workspaces.
For this PR, the behaviour is opted into by specifying
`--unstable-byonm`/`"unstable": ["byonm"]`, but in the future we may
make this the default behaviour as outlined in
https://github.com/denoland/deno/issues/18967#issuecomment-1761248941
This is an extremely rough initial implementation. Errors are
terrible in this and the LSP requires frequent restarts. Improvements
will be done in follow up PRs.
This commit introduces "WatcherCommunicator" struct that
is used facilitate bi-directional communication between CLI
file watcher and the watched function.
Prerequisite for https://github.com/denoland/deno/pull/20876
This brings in [`display`](https://github.com/rgbkrk/display.js) as part
of the `Deno.jupyter` namespace.
Additionally these APIs were added:
- "Deno.jupyter.md"
- "Deno.jupyter.html"
- "Deno.jupyter.svg"
- "Deno.jupyter.format"
These APIs greatly extend capabilities of rendering output in Jupyter
notebooks.
---------
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>
This fixes #20767.
We were losing `this` and then when an exception was happening, it
didn't show up in the output because we weren't bubbling up exceptions
from within a user defined function for displaying. I thought about
doing a `.call(object)` but didn't want to get in the way of a bound
`this` that a user or library was already putting on the function.
Adds `buffers` to the `Deno.jupyter.broadcast` API to send binary data
via comms. This affords the ability to send binary data via websockets
to the jupyter widget frontend.
This makes `CliNpmResolver` a trait. The terminology used is:
- **managed** - Deno manages the node_modules folder and does an
auto-install (ex. `ManagedCliNpmResolver`)
- **byonm** - "Bring your own node_modules" (ex. `ByonmCliNpmResolver`,
which is in this PR, but unimplemented at the moment)
Part of #18967
Closes #20535.
# Screenshots
## JSON
<img width="779" alt="image"
src="https://github.com/denoland/deno/assets/836375/668bb1a6-3f76-4b36-974e-cdc6c93f94c3">
## Vegalite
<img width="558" alt="image"
src="https://github.com/denoland/deno/assets/836375/a5e70908-6b87-42d8-85c3-1323ad52a00f">
# Implementation
Instead of going the route of recursively getting all the objects under
`application/.*json` keys, I went with `JSON.stringify`ing in denospace
then parsing it from rust. One of the key benefits of serializing and
deserializing is that non-JSON-able entries will get stripped
automatically. This also keeps the code pretty simple.
In the future we should _only_ do this for `application/.*json` keys.
cc @mmastrac
"Fixes" the exception display issue of #20524 on older versions of
Jupyter that required `evalue` to be truthy. For now, until we can do
proper processing of the `ExceptionDetails` this will make Jupyter
Notebook 6.5.1 and below happy.
This is the alternative "just work now" PR to #20530
This commit adds "deno jupyter" subcommand which
provides a Deno kernel for Jupyter notebooks.
The implementation is mostly based on Deno's REPL and
reuses large parts of it (though there's some clean up that
needs to happen in follow up PRs). Not all functionality of
Jupyter kernel is implemented and some message type
are still not implemented (eg. "inspect_request") but
the kernel is fully working and provides all the capatibilities
that the Deno REPL has; including TypeScript transpilation
and npm packages support.
Closes https://github.com/denoland/deno/issues/13016
---------
Co-authored-by: Adam Powers <apowers@ato.ms>
Co-authored-by: Kyle Kelley <rgbkrk@gmail.com>
### What
Skip writing files from the template if the files already exist in the
project directory.
### Why
When I run deno init in a directory that already has a main.ts, or one
of the other template files, I usually want to initialize a workspace
around a file I've started working in. A hard error in this case seems
counter productive. An informational message about what's being skipped
seems sufficient.
Close #20433
Previously:
```rust
pub struct TestDefinition {
pub id: String,
pub name: String,
pub range: SourceRange,
pub steps: Vec<TestDefinition>,
}
pub struct TestDefinitions {
pub discovered: Vec<TestDefinition>,
pub injected: Vec<lsp_custom::TestData>,
pub script_version: String,
}
```
Now:
```rust
pub struct TestDefinition {
pub id: String,
pub name: String,
pub range: Option<Range>,
pub is_dynamic: bool, // True for 'injected' module, not statically detected but added at runtime.
pub parent_id: Option<String>,
pub step_ids: HashSet<String>,
}
pub struct TestModule {
pub specifier: ModuleSpecifier,
pub script_version: String,
pub defs: HashMap<String, TestDefinition>,
}
```
Storing the test tree as a literal tree diminishes the value of IDs,
even though vscode stores them that way. This makes all data easily
accessible from `TestModule`. It unifies the interface between
'discovered' and 'injected' tests. This unblocks some enhancements wrt
syncing tests between the LSP and extension, such as this TODO:
61f08d5a71/client/src/testing.ts (L251-L259)
and https://github.com/denoland/vscode_deno/issues/900. We should also
get more flexibility overall.
`TestCollector` is cleaned up, now stores a `&mut TestModule` directly
and registers tests as it comes across them with
`TestModule::register()`. This method ensures sanity in the redundant
data from having both of `TestDefinition::{parent_id,step_ids}`.
All of the messy conversions between `TestDescription`,
`LspTestDescription`, `TestDefinition`, `TestData` and `TestIdentifier`
are cleaned up. They shouldn't have been using `impl From` and now the
full list of tests is available to their implementations.
The motivation is If I'm using deno lint --rules, I want to see all the
rules especially the one that have no tags, since the recommend ones are
already active
This change also prints the tags associated with the rule inline.
<!--
Before submitting a PR, please read https://deno.com/manual/contributing
1. Give the PR a descriptive title.
Examples of good title:
- fix(std/http): Fix race condition in server
- docs(console): Update docstrings
- feat(doc): Handle nested reexports
Examples of bad title:
- fix #7123
- update docs
- fix bugs
2. Ensure there is a related issue and it is referenced in the PR text.
3. Ensure there are tests that cover the changes.
4. Ensure `cargo test` passes.
5. Ensure `./tools/format.js` passes without changing files.
6. Ensure `./tools/lint.js` passes.
7. Open as a draft PR if your work is still in progress. The CI won't
run
all steps, but you can add '[ci]' to a commit message to force it to.
8. If you would like to run the benchmarks on the CI, add the 'ci-bench'
label.
-->
As the title.
---------
Co-authored-by: Matt Mastracci <matthew@mastracci.com>
Disables `BenchContext::start()` and `BenchContext::end()` for low
precision benchmarks (less than 0.01s per iteration). Prints a warning
when they are used in such benchmarks, suggesting to remove them.
```ts
Deno.bench("noop", { group: "noops" }, () => {});
Deno.bench("noop with start/end", { group: "noops" }, (b) => {
b.start();
b.end();
});
```
Before:
```
cpu: 12th Gen Intel(R) Core(TM) i9-12900K
runtime: deno 1.36.2 (x86_64-unknown-linux-gnu)
file:///home/nayeem/projects/deno/temp3.ts
benchmark time (avg) iter/s (min … max) p75 p99 p995
----------------------------------------------------------------------------- -----------------------------
noop 2.63 ns/iter 380,674,131.4 (2.45 ns … 27.78 ns) 2.55 ns 4.03 ns 5.33 ns
noop with start and end 302.47 ns/iter 3,306,146.0 (200 ns … 151.2 µs) 300 ns 400 ns 400 ns
summary
noop
115.14x faster than noop with start and end
```
After:
```
cpu: 12th Gen Intel(R) Core(TM) i9-12900K
runtime: deno 1.36.1 (x86_64-unknown-linux-gnu)
file:///home/nayeem/projects/deno/temp3.ts
benchmark time (avg) iter/s (min … max) p75 p99 p995
----------------------------------------------------------------------------- -----------------------------
noop 3.01 ns/iter 332,565,561.7 (2.73 ns … 29.54 ns) 2.93 ns 5.29 ns 7.45 ns
noop with start and end 7.73 ns/iter 129,291,091.5 (6.61 ns … 46.76 ns) 7.87 ns 13.12 ns 15.32 ns
Warning start() and end() calls in "noop with start and end" are ignored because it averages less than 0.01s per iteration. Remove them for better results.
summary
noop
2.57x faster than noop with start and end
```
This PR adds a test reporter for the [Test Anything
Protocol](https://testanything.org).
It makes the following implementation decisions:
- No TODO pragma, as there is no such marker in `Deno.test`
- SKIP pragma for `ignore`d tests
- Test steps are treated as TAP14 subtests
- Support for this in consumers seems spotty
- Some consumers will incorrectly interpret these markers, resulting in
unexpected output
- Considering the lack of support, and to avoid implementation
complexity,
subtests are at most one level deep (all test steps are in the same
subtest)
- To accommodate consumers that use comments to indicate test-suites
(unspecced)
- The test module path is output as a comment
- This is disabled for `--parallel` testing
- Failure diagnostics are output as JSON, which is also valid YAML
- The structure is not specified, so the format roughly follows the spec
example:
```
---
message: "Failed with error 'hostname peebles.example.com not found'"
severity: fail
found:
hostname: 'peebles.example.com'
address: ~
wanted:
hostname: 'peebles.example.com'
address: '85.193.201.85'
at:
file: test/dns-resolve.c
line: 142
...
```
Some people might get think they need to import from this directory,
which could cause confusion and duplicate dependencies. Additionally,
the `vendor` directory has special behaviour in the language server, so
importing from the folder will definitely cause confusion and issues
there.
To fix bugs around detection of when node emulation is required, we will
just eagerly initialize it. The improvements we make to reduce the
impact of the startup time:
- [x] Process stdin/stdout/stderr are lazily created
- [x] node.js global proxy no longer allocates on each access check
- [x] Process checks for `beforeExit` listeners before doing expensive
shutdown work
- [x] Process should avoid adding global event handlers until listeners
are added
Benchmarking this PR (`89de7e1ff`) vs main (`41cad2179`)
```
12:36 $ third_party/prebuilt/mac/hyperfine --warmup 100 -S none './deno-41cad2179 run ./empty.js' './deno-89de7e1ff run ./empty.js'
Benchmark 1: ./deno-41cad2179 run ./empty.js
Time (mean ± σ): 24.3 ms ± 1.6 ms [User: 16.2 ms, System: 6.0 ms]
Range (min … max): 21.1 ms … 29.1 ms 115 runs
Benchmark 2: ./deno-89de7e1ff run ./empty.js
Time (mean ± σ): 24.0 ms ± 1.4 ms [User: 16.3 ms, System: 5.6 ms]
Range (min … max): 21.3 ms … 28.6 ms 126 runs
```
Fixes https://github.com/denoland/deno/issues/20142
Fixes https://github.com/denoland/deno/issues/15826
Fixes https://github.com/denoland/deno/issues/20028
Renames the unstable `deno_modules` directory and corresponding settings
to `vendor` after feedback. Also causes the vendoring of the
`node_modules` directory which can be disabled via
`--node-modules-dir=false` or `"nodeModulesDir": false`.
This commit adds a "dot" reporter to "deno test" subcommand,
that can be activated using "--dot" flag.
It provides a concise output using:
- "." for passing test
- "," for ignored test
- "!" for failing test
User output is silenced and not printed to the console.
In non-TTY environments each result is printed on a separate line.
This commit makes the following changes
- Created a `CompoundTestReporter` to allow us to use multiple reporters
- Implements `JUnitTestReporter` which writes JUnit XML to a path
- Added a CLI flag/option `--junit` that enables JUnit reporting. By
default this writes the report to `stdout` (and disables pretty
reporting). If a path is provided, it will write the JUnit report to
that file while the pretty reporter writes to stdout like normal
Output of `deno -- test --allow-all --unstable
--location=http://js-unit-tests/foo/bar --junit
cli/tests/unit/testing_test.ts `
```xml
<?xml version="1.0" encoding="UTF-8"?>
<testsuites name="deno test" tests="7" failures="0" errors="0" time="0.176">
<testsuite name="file:///Users/cooper/deno/deno/cli/tests/unit/testing_test.ts" tests="7" disabled="0" errors="0" failures="0">
<testcase name="testWrongOverloads" time="0.012">
</testcase>
<testcase name="nameOfTestCaseCantBeEmpty" time="0.009">
</testcase>
<testcase name="invalidStepArguments" time="0.008">
</testcase>
<testcase name="nameOnTextContext" time="0.029">
<properties>
<property name="step[passed]" value="step ... nested step"/>
<property name="step[passed]" value="step"/>
</properties>
</testcase>
<testcase name="originOnTextContext" time="0.030">
<properties>
<property name="step[passed]" value="step ... nested step"/>
<property name="step[passed]" value="step"/>
</properties>
</testcase>
<testcase name="parentOnTextContext" time="0.030">
<properties>
<property name="step[passed]" value="step ... nested step"/>
<property name="step[passed]" value="step"/>
</properties>
</testcase>
<testcase name="explicit undefined for boolean options" time="0.009">
</testcase>
</testsuite>
</testsuites>
```
Closes https://github.com/denoland/deno/issues/15277
This commit adds a single "warmup" run of empty function when running
`deno bench`.
This change will break so-called "JIT bias" which makes V8 optimize the
first function
and then bail out of optimization on second function. In essence the
"warmup" function
is getting optimized and then all user benches are bailed out of
optimization.
This PR breaks the addition of the `TestReporter` trait and refactoring
of `PrettyTestReporter` out of #19747. The goal is to enable the
addition of test reporters, including machine readable output.
…nclusion" (#19519)"
This reverts commit 28a4f3d0f5.
This change causes failures when used outside Deno repo:
```
============================================================
Deno has panicked. This is a bug in Deno. Please report this
at https://github.com/denoland/deno/issues/new.
If you can reliably reproduce this panic, include the
reproduction steps and re-run with the RUST_BACKTRACE=1 env
var set and include the backtrace in your report.
Platform: linux x86_64
Version: 1.34.3+b37b286
Args: ["/opt/hostedtoolcache/deno/0.0.0-b37b286f7fa68d5656f7c180f6127bdc38cf2cf5/x64/deno", "test", "--doc", "--unstable", "--allow-all", "--coverage=./cov"]
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Failed to read "/home/runner/work/deno/deno/core/00_primordials.js"
Caused by:
No such file or directory (os error 2)', core/runtime/jsruntime.rs:699:8
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
Relands #19463. This time the `ExtensionFileSourceCode` enum is
preserved, so this effectively just splits feature
`include_js_for_snapshotting` into `exclude_js_sources` and
`runtime_js_sources`, adds a `force_include_js_sources` option on
`extension!()`, and unifies `ext::Init_ops_and_esm()` and
`ext::init_ops()` into `ext::init()`.
… (#19463)"
This reverts commit ceb03cfb03.
This is being reverted because it causes 3.5Mb increase in the binary
size,
due to runtime JS code being included in the binary, even though it's
already snapshotted.
CC @nayeemrmn
Remove `ExtensionFileSourceCode::LoadedFromFsDuringSnapshot` and feature
`include_js_for_snapshotting` since they leak paths that are only
applicable in this repo to embedders. Replace with feature
`exclude_js_sources`. Additionally the feature
`force_include_js_sources` allows negating it, if both features are set.
We need both of these because features are additive and there must be a
way of force including sources for snapshot creation while still having
the `exclude_js_sources` feature. `force_include_js_sources` is only set
for build deps, so sources are still excluded from the final binary.
You can also specify `force_include_js_sources` on any extension to
override the above features for that extension. Towards #19398.
But there was still the snapshot-from-snapshot situation where code
could be executed twice, I addressed that by making `mod_evaluate()` and
scripts like `core/01_core.js` behave idempotently. This allowed
unifying `ext::init_ops()` and `ext::init_ops_and_esm()` into
`ext::init()`.
This commit migrates "deno_core" from using "FuturesUnordered" to
"tokio::task::JoinSet". This makes every op to be a separate Tokio task
and should unlock better utilization of kqueue/epoll.
There were two quirks added to this PR:
- because of the fact that "JoinSet" immediately polls spawn tasks,
op sanitizers can give false positives in some cases, this was
alleviated by polling event loop once before running a test with
"deno test", which gives canceled ops an opportunity to settle
- "JsRuntimeState::waker" was moved to "OpState::waker" so that FFI
API can still use threadsafe functions - without this change the
registered wakers were wrong as they would not wake up the
whole "JsRuntime" but the task associated with an op
---------
Co-authored-by: Matt Mastracci <matthew@mastracci.com>
When someone explicitly opts into using the node_modules dir via
`--node-modules-dir` or setting `"nodeModulesDir": true` in the
deno.json file, we should eagerly ensure a top level package.json
install is done on startup. This was initially always done when we added
package.json support and a package.json was auto-discovered, but scaled
it back to be lazily done when a bare specifier matched an entry in the
package.json because of how disruptive it was for people using Deno
scripts in Node projects. That said, it does not make sense for someone
to opt-into having deno control and use their node_modules directory and
not want a package.json install to occur. If such a rare scenario
exists, the `DENO_NO_PACKAGE_JSON=1` environment variable can be set.
Ideally, we would only ever use a node_modules directory with this
explicit opt-in so everything is very clear, but we still have this
automatic scenario when there's a package.json in order to make more
node projects work out of the box.
