Volt 0.19: oxc 0.18, the error overlay, and priv npm vendoring

.gitattributes

@@ -0,0 +1 @@
+priv/ts/npm.lock linguist-generated

.github/workflows/ci.yml

@@ -21,6 +21,7 @@ jobs:
         sudo apt-get update
         sudo apt-get install --yes inotify-tools
         mix deps.get
+        mix volt.priv.vendor priv/ts
         npm ci
         npx playwright install --with-deps chromium
       latest-command: MIX_ENV=dev mix lint && MIX_ENV=test mix test

.gitignore

@@ -30,3 +30,4 @@ volt-*.tar
 
 # Git worktrees for parallel agent work
 .worktrees/
+/priv/ts/node_modules/

.reach.exs

@@ -139,6 +139,9 @@ infrastructure = [
   "Volt.Cache",
   "Volt.Dev",
   "Volt.Dev.Cleanup",
+  "Volt.Dev.Error",
+  "Volt.Priv.Vendor",
+  "Volt.DevServer.ClientTag",
   "Volt.Dev.Assets",
   "Volt.Dev.Session.Call",
   "Volt.Dev.Session.State",
@@ -147,6 +150,7 @@ infrastructure = [
   "Volt.Dev.ConsoleForwarder.Payload",
   "Volt.ETS",
   "Volt.HMR.Boundary",
+  "Volt.HMR.Errors",
   "Volt.HMR.GlobGraph",
   "Volt.HMR.ImportGraph",
   "Volt.HMR.ModuleGraph",

CHANGELOG.md

@@ -2,6 +2,36 @@
 
 ## Unreleased
 
+### Breaking changes
+
+- Lint diagnostics are `OXC.Diagnostic` maps: severities are `:error` and `:warning`, and locations are 1-based `position` and `span` instead of byte offsets. Parse errors are diagnostics too, without a `rule`.
+- Lint `:plugins`, `:env`, and `:globals` take names as strings, as in an oxlint config file, such as `plugins: ["typescript", "react"]` and `env: ["browser"]`. Atom names raise an `ArgumentError`.
+- Custom lint rules report findings with AST `start` and `end` offsets instead of `span`.
+- `Volt.JS.Transforms.Imports.rewrite!/3` raises `OXC.Error` on parse errors.
+- HMR `error` messages carry the current `errors` as `Volt.Dev.Error` entries instead of a `path` and `reason`; an empty list hides the overlay.
+
+### Added
+
+- The error overlay shows each error's file, line, column, source frame, and hint.
+- The error overlay is a `<volt-error-overlay>` element rendered with lit-html into a Shadow DOM, so the app's styles cannot affect it.
+- Highlight the error overlay's source frame with the optional `lumis` dependency and its parser packages, such as `lumis_wasm_typescript`.
+- `Volt.HMR.error/3` takes a `:title` for the overlay heading, such as `"Render error"`. `Volt.HMR.clear_error/2` hides errors reported with `Volt.HMR.error/3`. Errors stay current until cleared, so browsers that connect later show them.
+- The dev server adds the HMR client to HTML pages the app renders.
+- `mix volt.priv.vendor` vendors npm packages for browser code under `priv`, keeping only the files the sources reach, for the Hex package rather than git. `Volt.Priv.bundle!/3` bundles a `priv` entry with them and vendors on first use in a git or path checkout. See "Browser code with npm packages" in the plugins guide.
+- The error overlay shows a diagnostic's stacktrace.
+
+### Changed
+
+- Require `oxc` 0.18.1, `vize` 0.15, `quickbeam` 0.11.2, and `json_codec` 0.3.
+
+### Fixed
+
+- Show the error overlay when a page loads with a module that fails to compile. The client previously loaded only through the failing module graph.
+- Hide the overlay once errors are fixed, and report Tailwind build failures, including at startup.
+- Reload the page after the HMR connection returns, since the server may have restarted.
+- Type-aware checks run the type-aware rules that lint categories such as `"correctness"` select, honoring individual rule settings and per-file overrides ([#40](https://github.com/elixir-volt/volt/issues/40)).
+- Type-aware checks extract single-file component scripts with the configured Volt plugins instead of the oxlint plugin names.
+
 ## 0.18.1 - 2026-09-15
 
 ### Added

config/config.exs

@@ -9,7 +9,7 @@ config :volt, :format,
   arrow_parens: :always
 
 config :volt, :lint,
-  plugins: [:typescript, :import, :unicorn],
+  plugins: ["typescript", "import", "unicorn"],
   rules: %{
     "no-unused-expressions" => :allow,
     "no-unused-vars" => :warn,

examples/react/config/config.exs

@@ -38,7 +38,7 @@ config :volt, :format,
   single_quote: true
 
 config :volt, :lint,
-  plugins: [:typescript, :react],
+  plugins: ["typescript", "react"],
   tsgolint: System.find_executable("tsgolint"),
   rules: %{
     "correctness" => :deny,

examples/solid/config/config.exs

@@ -38,7 +38,7 @@ config :volt, :format,
   single_quote: true
 
 config :volt, :lint,
-  plugins: [:typescript],
+  plugins: ["typescript"],
   tsgolint: System.find_executable("tsgolint"),
   rules: %{
     "correctness" => :deny,

examples/svelte/config/config.exs

@@ -37,7 +37,7 @@ config :volt, :format,
   single_quote: true
 
 config :volt, :lint,
-  plugins: [:typescript],
+  plugins: ["typescript"],
   tsgolint: System.find_executable("tsgolint"),
   rules: %{
     "correctness" => :deny,

examples/vanilla/config/config.exs

@@ -37,7 +37,7 @@ config :volt, :format,
   single_quote: true
 
 config :volt, :lint,
-  plugins: [:typescript],
+  plugins: ["typescript"],
   tsgolint: System.find_executable("tsgolint"),
   rules: %{
     "correctness" => :deny,

examples/vanilla/mix.exs

@@ -36,7 +36,9 @@ defmodule VanillaExample.MixProject do
       {:jason, "~> 1.2"},
       {:dns_cluster, "~> 0.2.0"},
       {:bandit, ">= 1.12.5 and < 2.0.0"},
-      {:volt, path: "../..", override: true}
+      {:volt, path: "../..", override: true},
+      {:lumis, "~> 0.10", only: :dev},
+      {:lumis_wasm_typescript, "~> 0.26", only: :dev}
     ]
   end