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eitsupi merged 2 commits into from
Jul 1, 2026
Merged

docs(server): document Windows -A requirement for named pipes #70

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2662e36
docs(server): document Windows -A requirement for named pipes, add --…
eitsupi Jul 1, 2026
1dcc342
docs(server): fix inaccurate --tcp scoping claim in deno.json comment
eitsupi Jul 1, 2026
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19 changes: 18 additions & 1 deletion README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -99,7 +99,11 @@ First [install Deno](https://docs.deno.com/runtime/getting_started/installation/
then run directly (dependencies are fetched automatically):

```bash
deno run https://raw.githubusercontent.com/grantmcdermott/jgd/refs/heads/main/server/main.ts
# macOS / Linux
deno run --allow-net --allow-read --allow-write --allow-env https://raw.githubusercontent.com/grantmcdermott/jgd/refs/heads/main/server/main.ts

# Windows
deno run -A https://raw.githubusercontent.com/grantmcdermott/jgd/refs/heads/main/server/main.ts
```

Or, clone the repo and run locally:
Expand All @@ -109,6 +113,19 @@ Or, clone the repo and run locally:
cd server && deno task start && cd ..
```

> [!NOTE]
> On **Windows**, R connections default to a named pipe, and Deno has no
> permission combination narrower than `-A` (`--allow-all`) that can satisfy
> binding one — that's why the Windows command above needs it (`deno task
> start` above already grants `-A` for the same reason).
>
> To keep permissions scoped on Windows instead, add `--tcp <port>` (e.g.
> `--tcp 8888`) to connect over localhost TCP rather than a named pipe:
>
> ```bash
> deno run --allow-net --allow-read --allow-write --allow-env https://raw.githubusercontent.com/grantmcdermott/jgd/refs/heads/main/server/main.ts --tcp 8888
> ```

Once the Deno server is running, open `http://127.0.0.1:<port>/`
in your browser (the URL is printed on startup). Then you start executing
plotting commands from any R session.
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29 changes: 14 additions & 15 deletions server/deno.json
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Expand Up @@ -8,24 +8,23 @@
"@astral/astral": "jsr:@astral/astral@^0.5"
},
"tasks": {
// --allow-net is unrestricted (not scoped to 127.0.0.1): since Deno
// PR denoland/deno#34395, Deno.listen/connect({transport:"unix"}) also
// requires an --allow-net=unix:<path> grant, in addition to
// --allow-read/--allow-write, to bind/connect the R unix socket. The
// socket path is randomly generated at runtime when --socket isn't
// passed explicitly, so it can't be allow-listed up front; unscoped
// --allow-net is the documented escape hatch for that case.
"start": "deno run --allow-net --allow-read --allow-write --allow-env main.ts",
"dev": "deno run --allow-net --allow-read --allow-write --allow-env --watch main.ts",
// -A is required here (not just --allow-net/read/write/env): on Windows,
// node:net's PipeWrap.bind/listen/connect (used for named pipes) routes
// -A (--allow-all) is required on Windows: R connections default to a
// named pipe there, and node:net's PipeWrap.bind/listen/connect routes
// any non-drive-letter path like \\.\pipe\... through Deno's permission
// checker's check_special_file, which demands every permission category
// (read/write/net/env/sys/run/ffi/import) be fully granted -- i.e. -A
// itself, with no narrower combination accepted. These tasks exercise
// that code path directly (in-process pipe tests) or indirectly (via
// TestServer spawning main.ts), so they need -A on Windows; -A here for
// all platforms keeps the task portable without OS-specific branching.
// itself, with no narrower combination accepted. Separately, on
// Linux/macOS, Deno.listen({transport:"unix"}) requires an unscoped
// --allow-net (since denoland/deno#34395) because the R socket path is
// randomly generated at runtime and can't be allow-listed up front.
// -A satisfies both without OS-specific branching (deno.json tasks
// can't conditionally vary flags by platform). -A is hardcoded into
// these tasks, so passing --tcp <port> here does NOT narrow permissions
// (deno task start -- --tcp 8888 still runs with -A). To actually get
// scoped permissions with --tcp, invoke `deno run` directly instead of
// this task -- see the README's Deno-server quick-start section.
"start": "deno run -A main.ts",
"dev": "deno run -A --watch main.ts",
"test": "deno test -A --parallel --ignore=tests/e2e tests/",
"test:e2e": "deno test -A tests/e2e/",
"test:all": "deno task test && deno task test:e2e"
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