flash-extensions/flash-ext-vite/docs/README.md

@@ -55,6 +55,7 @@ in agreement.
 | `root(Path)` | `web` | The Vite project, relative to the working directory. DEV only. |
 | `devPort(int)` | `5173` | Vite's port in DEV. |
 | `basePath(String)` | `/` | Where the frontend is served. Vite's `base` must match it. |
+| `navigationOnly(boolean)` | `true` | Only browser navigations fall back to `index.html` (see below). `false` gives every `GET` that matches no file the page, as nginx's `try_files` does, which also turns API 404s into the page. Rarely wanted. |
 
 | Plugin parameter | Default | |
 |---|---|---|
@@ -103,11 +104,18 @@ prefers specific routes over the wildcard.
 | `basePath` itself (`/`) | `index.html`, whatever the client accepts |
 | a built file under `assets/` | `Cache-Control: public, max-age=31536000, immutable`, no `ETag` (it is never asked for again) |
 | any other built file (`index.html`, `favicon.svg`, …) | `Cache-Control: no-cache`, revalidated by `ETag` |
-| no such file, and `Accept` names `text/html` (a browser navigating to `/content/2`) | `index.html`, so the client-side router takes it |
+| no such file, and the request is a navigation | `index.html`, so the client-side router takes it |
 | no such file otherwise (a `fetch` to `/api/typo`, a missing script) | the app's own `404` |
 | `If-None-Match` with the current `ETag` | `304` with `ETag` and `Cache-Control`, no body |
 | `HEAD` | the `GET` headers, `Content-Length` included, no body |
 
+A navigation is what a browser sends when a person opens a URL: `Sec-Fetch-Mode: navigate`, which
+every current browser sets for exactly this purpose, or an `Accept` that names `text/html`, which
+covers older browsers, crawlers and `curl -H 'Accept: text/html'`. The check reads the header bytes
+in place and allocates nothing. This is stricter than Vite's own dev-server fallback, which also
+takes `Accept: */*` and so gives `fetch('/api/typo')` the page. It is the same rule service
+workers use for their navigation fallback. With `navigationOnly(false)` the check is skipped.
+
 A `.gz` beside a file is its gzipped form: the plugin writes one for every text file of 1 KB and
 more, and it is sent to clients whose `Accept-Encoding` allows gzip (`gzip;q=0` does not), with
 `Vary: Accept-Encoding`.

flash-extensions/flash-ext-vite/src/main/java/dev/relism/flash/ext/vite/Assets.java

@@ -5,6 +5,7 @@ import dev.relism.flash.http.HttpStatus;
 import dev.relism.flash.models.PreEncodedHeader;
 import dev.relism.flash.models.Request;
 import dev.relism.flash.models.Response;
+import dev.relism.fpr.core.ByteView;
 
 import java.io.IOException;
 import java.net.URI;
@@ -59,13 +60,22 @@ final class Assets {
             Map.entry("otf", "font/otf"),
             Map.entry("wasm", "application/wasm"));
 
-    record Asset(byte[] raw, byte[] gzip, byte[] type, PreEncodedHeader cache, PreEncodedHeader etag, String tag) {}
+    private static final byte[] HTML = ascii("text/html");
+    private static final byte[] GZIP_TOKEN = ascii("gzip");
+    private static final byte[] Q = ascii("q=");
+
+    record Asset(byte[] raw, byte[] gzip, byte[] type, PreEncodedHeader cache, PreEncodedHeader etag, byte[] tag) {}
 
     final Map<String, Asset> byPath;
     private final Asset index;
+    private final boolean navigationOnly;
 
-    /** Every file under {@link ViteExtension#CLASSPATH} on {@code loader}'s classpath, routed under {@code basePath}. */
-    Assets(ClassLoader loader, String basePath) {
+    /**
+     * Every file under {@link ViteExtension#CLASSPATH} on {@code loader}'s classpath, routed under
+     * {@code basePath}; {@code navigationOnly} as in {@link ViteExtension#navigationOnly}.
+     */
+    Assets(ClassLoader loader, String basePath, boolean navigationOnly) {
+        this.navigationOnly = navigationOnly;
         URL index = loader.getResource(ViteExtension.CLASSPATH + "/index.html");
         if (index == null) {
             throw new IllegalStateException("No built frontend on the classpath (" + ViteExtension.CLASSPATH + "/index.html): "
@@ -107,22 +117,20 @@ final class Assets {
     }
 
     /**
-     * The asset at the request's path. A path that is none is a client-side route when a browser
-     * navigates to it ({@code Accept} names HTML), so it gets {@code index.html}; for anything
-     * else, an API call or a missing script, it is the app's own 404.
+     * The asset at the request's path. A path that is none gets {@code index.html} when a browser
+     * navigates to it, so the client-side router takes it; anything else, an API call or a missing
+     * script, gets the app's own 404. Headers are read as bytes, so nothing here allocates.
      */
     void serve(Request req, Response res) {
         Asset asset = byPath.get(req.path());
         if (asset == null) {
-            String accept = req.header("Accept");
-            if (accept == null || !accept.contains("text/html")) throw HttpException.notFound(req.path());
+            if (navigationOnly && !navigation(req)) throw HttpException.notFound(req.path());
             asset = index;
         }
         res.header(asset.cache);
         if (asset.etag != null) {
             res.header(asset.etag);
-            String known = req.header("If-None-Match");
-            if (known != null && known.contains(asset.tag)) {
+            if (indexOf(req.headerView("If-None-Match"), asset.tag, 0) >= 0) {
                 res.status(HttpStatus.NOT_MODIFIED);
                 return;
             }
@@ -130,7 +138,7 @@ final class Assets {
         res.type(asset.type);
         if (asset.gzip != null) {
             res.header(VARY);
-            if (acceptsGzip(req.header("Accept-Encoding"))) {
+            if (acceptsGzip(req.headerView("Accept-Encoding"))) {
                 res.header(GZIP).body(asset.gzip);
                 return;
             }
@@ -138,33 +146,58 @@ final class Assets {
         res.body(asset.raw);
     }
 
+    /** What browsers send when a person opens a URL: {@code Sec-Fetch-Mode}, or {@code Accept} naming HTML for older clients. */
+    static boolean navigation(Request req) {
+        return req.headerEquals("Sec-Fetch-Mode", "navigate") || indexOf(req.headerView("Accept"), HTML, 0) >= 0;
+    }
+
     /** Listed in {@code Accept-Encoding}, and not with a q of zero. */
-    static boolean acceptsGzip(String accept) {
-        if (accept == null) return false;
-        int at = accept.indexOf("gzip");
+    static boolean acceptsGzip(ByteView accept) {
+        int at = indexOf(accept, GZIP_TOKEN, 0);
         if (at < 0) return false;
-        int end = accept.indexOf(',', at);
-        if (end < 0) end = accept.length();
-        int q = accept.indexOf("q=", at);
+        int end = at;
+        while (end < accept.length() && accept.byteAt(end) != ',') end++;
+        int q = indexOf(accept, Q, at);
         if (q < 0 || q > end) return true;
         for (int i = q + 2; i < end; i++) {
-            char c = accept.charAt(i);
+            byte c = accept.byteAt(i);
             if (c >= '1' && c <= '9') return true;
             if (c != '0' && c != '.') break;
         }
         return false;
     }
 
+    /**
+     * Where lowercase {@code needle} starts in {@code view} at or after {@code from}, ASCII case
+     * ignored, or -1 (also for a missing header). Folding with {@code | 0x20} leaves digits, quotes
+     * and slashes as they are, which is all the needles here contain besides letters.
+     */
+    static int indexOf(ByteView view, byte[] needle, int from) {
+        if (view == null) return -1;
+        outer:
+        for (int i = from, last = view.length() - needle.length; i <= last; i++) {
+            for (int j = 0; j < needle.length; j++) {
+                if ((view.byteAt(i + j) | 0x20) != needle[j]) continue outer;
+            }
+            return i;
+        }
+        return -1;
+    }
+
     /**
      * Vite puts every content-hashed file under {@code assets/}: those never change, so they are
      * cached for good and never revalidated, and need no ETag. The rest revalidate by one.
      */
     private static Asset asset(String path, byte[] raw, byte[] gzip) {
         String extension = path.substring(path.lastIndexOf('.') + 1).toLowerCase();
-        byte[] type = TYPES.getOrDefault(extension, "application/octet-stream").getBytes(StandardCharsets.US_ASCII);
+        byte[] type = ascii(TYPES.getOrDefault(extension, "application/octet-stream"));
         if (path.startsWith("assets/")) return new Asset(raw, gzip, type, IMMUTABLE, null, null);
         String tag = "\"" + HexFormat.of().formatHex(sha1(raw)) + "\"";
-        return new Asset(raw, gzip, type, REVALIDATE, new PreEncodedHeader("ETag", tag), tag);
+        return new Asset(raw, gzip, type, REVALIDATE, new PreEncodedHeader("ETag", tag), ascii(tag));
+    }
+
+    private static byte[] ascii(String text) {
+        return text.getBytes(StandardCharsets.US_ASCII);
     }
 
     private static byte[] sha1(byte[] raw) {

flash-extensions/flash-ext-vite/src/main/java/dev/relism/flash/ext/vite/ViteExtension.java

@@ -20,6 +20,7 @@ public final class ViteExtension implements FlashExtension {
     private Path root = Path.of("web");
     private int devPort = 5173;
     private String basePath = "/";
+    private boolean navigationOnly = true;
 
     /** The Vite project, {@code web} (relative to the working directory) by default. Read in DEV only. */
     public ViteExtension root(Path root) {
@@ -40,13 +41,23 @@ public final class ViteExtension implements FlashExtension {
         return this;
     }
 
+    /**
+     * Whether only a browser navigation to a path that is no file gets {@code index.html}, {@code
+     * true} by default, so an API call to a missing route gets a 404 rather than the page. {@code
+     * false} serves the page for every such {@code GET}, as nginx's {@code try_files} would.
+     */
+    public ViteExtension navigationOnly(boolean navigationOnly) {
+        this.navigationOnly = navigationOnly;
+        return this;
+    }
+
     @Override
     public void configure(FlashRegistrar<?> app, FlashContext ctx) {
         if (Flash.DEV) {
             ctx.onClose(new DevServer(root, devPort)::close);
             return;
         }
-        Assets assets = new Assets(ViteExtension.class.getClassLoader(), basePath);
+        Assets assets = new Assets(ViteExtension.class.getClassLoader(), basePath, navigationOnly);
         String everything = "/".equals(basePath) ? "/**" : basePath + "/**";
         ctx.onReady(() -> {
             app.get(everything, (req, res) -> {

flash-extensions/flash-ext-vite/src/test/java/dev/relism/flash/ext/vite/AssetsTest.java

@@ -1,5 +1,6 @@
 package dev.relism.flash.ext.vite;
 
+import dev.relism.fpr.core.ByteView;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -33,24 +34,41 @@ class AssetsTest {
             }
         }
         try (URLClassLoader loader = new URLClassLoader(new URL[]{jar.toUri().toURL()}, null)) {
-            assertEquals(Set.of("/", "/index.html", "/assets/a-12345678.css"), new Assets(loader, "/").byPath.keySet());
+            assertEquals(Set.of("/", "/index.html", "/assets/a-12345678.css"), new Assets(loader, "/", true).byPath.keySet());
         }
     }
 
     @Test
     void noBuildFailsTheBootNamingThePlugin() throws IOException {
         try (URLClassLoader empty = new URLClassLoader(new URL[0], null)) {
-            assertTrue(assertThrows(IllegalStateException.class, () -> new Assets(empty, "/")).getMessage().contains("flash-ext-vite-maven-plugin"));
+            assertTrue(assertThrows(IllegalStateException.class, () -> new Assets(empty, "/", true)).getMessage().contains("flash-ext-vite-maven-plugin"));
         }
     }
 
     @Test
     void gzipIsAcceptedUnlessRefused() {
-        assertTrue(Assets.acceptsGzip("gzip, deflate, br"));
-        assertTrue(Assets.acceptsGzip("br;q=1.0, gzip;q=0.5"));
-        assertFalse(Assets.acceptsGzip("gzip;q=0, br"));
-        assertFalse(Assets.acceptsGzip("gzip;q=0.000"));
-        assertFalse(Assets.acceptsGzip("br"));
+        assertTrue(Assets.acceptsGzip(view("gzip, deflate, br")));
+        assertTrue(Assets.acceptsGzip(view("br;q=1.0, GZIP;q=0.5")));
+        assertFalse(Assets.acceptsGzip(view("gzip;q=0, br")));
+        assertFalse(Assets.acceptsGzip(view("gzip;q=0.000")));
+        assertFalse(Assets.acceptsGzip(view("br")));
         assertFalse(Assets.acceptsGzip(null));
     }
+
+    @Test
+    void searchingIgnoresAsciiCaseAndFindsTheFirstMatch() {
+        byte[] html = "text/html".getBytes();
+        assertEquals(0, Assets.indexOf(view("Text/HTML,*/*"), html, 0));
+        assertEquals(12, Assets.indexOf(view("application/text/html"), html, 0));
+        assertEquals(-1, Assets.indexOf(view("text/htm"), html, 0));
+        assertEquals(-1, Assets.indexOf(null, html, 0));
+    }
+
+    private static ByteView view(String text) {
+        byte[] bytes = text.getBytes();
+        return new ByteView() {
+            @Override public int length() { return bytes.length; }
+            @Override public byte byteAt(int i) { return bytes[i]; }
+        };
+    }
 }

flash-extensions/flash-ext-vite/src/test/java/dev/relism/flash/ext/vite/ViteExtensionTest.java

@@ -16,6 +16,9 @@ class ViteExtensionTest {
     @RegisterExtension
     static final FlashTest app = FlashTest.of(flash -> flash.install(new ViteExtension()));
 
+    @RegisterExtension
+    static final FlashTest everything = FlashTest.of(flash -> flash.install(new ViteExtension().navigationOnly(false)));
+
     @RegisterExtension
     static final FlashTest nested = FlashTest.of(flash -> flash.install(new ViteExtension().basePath("/app/")));
 
@@ -41,6 +44,7 @@ class ViteExtensionTest {
         for (String route : new String[]{"/content/2", "/users/ada.lovelace"}) {
             app.request().header("Accept", NAVIGATION).get(route).expectStatus(200).expectHeader("Cache-Control", "no-cache").expectBodyContains("spa");
         }
+        app.request().header("Sec-Fetch-Mode", "navigate").get("/content/2").expectStatus(200).expectBodyContains("spa");
         app.request().header("Accept", "application/json").get("/api/nope").expectStatus(404);
         app.request().header("Accept", "*/*").get("/assets/missing.js").expectStatus(404);
         app.get("/content/2").expectStatus(404);
@@ -48,6 +52,13 @@ class ViteExtensionTest {
         nested.get("/app").expectStatus(200).expectBodyContains("spa");
     }
 
+    /** Opted out of the navigation check, every GET that is no file gets the page, as nginx's try_files would. */
+    @Test
+    void withoutTheNavigationCheckEveryMissGetsTheIndex() {
+        everything.request().header("Accept", "application/json").get("/api/nope").expectStatus(200).expectBodyContains("spa");
+        everything.get("/assets/missing.js").expectStatus(200).expectBodyContains("spa");
+    }
+
     @Test
     void anUnchangedFileIsNotSentAgainAHashedOneIsNeverAsked() {
         String etag = app.get("/favicon.svg").header("ETag");

flash/src/main/java/dev/relism/flash/models/Request.java

@@ -181,6 +181,12 @@ public class Request {
      */
     public String header(String name) { checkActive(); return requestLine.getHeaders().first(name); }
 
+    /**
+     * The first value of header {@code name} as a view over the request's own bytes, or {@code null}:
+     * {@link #header} without the {@code String}, for a hot path. Valid only while the handler runs.
+     */
+    public ByteView headerView(String name) { checkActive(); return requestLine.getHeaders().view(name); }
+
     /**
      * Returns all values of header {@code name} in declaration order.
      * Useful for headers that appear multiple times (e.g. {@code Accept}, {@code Cookie}).