3 files changed, 168 insertions, 0 deletions
diff --git a/src/index.ts b/src/index.ts
new file mode 100644
index 0000000..27ed46a
--- /dev/null
+++ b/src/index.ts
@@ -0,0 +1,41 @@
+import type {AstroIntegration, ContentEntryType, HookParameters} from "astro"
+import {fileURLToPath} from "url"
+import gemtextVitePlugin from "./vitePlugin.js"
+
+export const ext = "gmi"
+
+type SetupHookParams = HookParameters<"astro:config:setup"> & {
+    // `addPageExtension` and `contentEntryType` are not a public APIs
+    // Add type defs here
+    addPageExtension: (extension: string) => void
+    addContentEntryType: (contentEntryType: ContentEntryType) => void
+}
+
+export default function gemtext(): AstroIntegration {
+    return {
+        name: "astro-gemtext",
+        hooks: {
+            "astro:config:setup": async (_params) => {
+                const params = _params as SetupHookParams
+                params.addRenderer({
+                    name: "astro-gemtext",
+                    serverEntrypoint: fileURLToPath(
+                        new URL("./renderer.js", import.meta.url),
+                    ),
+                })
+                params.addPageExtension(ext)
+                params.addContentEntryType({
+                    extensions: [`.${ext}`],
+                    getEntryInfo: async (params) => {
+                        throw new Error("Not implemented")
+                    },
+                })
+                params.updateConfig({
+                    vite: {
+                        plugins: [gemtextVitePlugin()],
+                    },
+                })
+            },
+        },
+    }
+}
diff --git a/src/renderer.ts b/src/renderer.ts
new file mode 100644
index 0000000..677c234
--- /dev/null
+++ b/src/renderer.ts
@@ -0,0 +1,77 @@
+import type {NamedSSRLoadedRendererValue} from "astro"
+import {AstroError} from "astro/errors"
+import {AstroJSX, jsx} from "astro/jsx-runtime"
+import {renderJSX} from "astro/runtime/server/index.js"
+
+const slotName = (str: string) =>
+    str.trim().replace(/[-_]([a-z])/g, (_, w) => w.toUpperCase())
+
+// NOTE: In practice, MDX components are always tagged with `__astro_tag_component__`, so the right renderer
+// is used directly, and this check is not often used to return true.
+export async function check(
+    Component: any,
+    props: any,
+    {default: children = null, ...slotted} = {},
+) {
+    if (typeof Component !== "function") return false
+    const slots: Record<string, any> = {}
+    for (const [key, value] of Object.entries(slotted)) {
+        const name = slotName(key)
+        slots[name] = value
+    }
+    try {
+        const result = await Component({...props, ...slots, children})
+        return result[AstroJSX]
+    } catch (e) {
+        throwEnhancedErrorIfMdxComponent(e as Error, Component)
+    }
+    return false
+}
+
+export async function renderToStaticMarkup(
+    this: any,
+    Component: any,
+    props = {},
+    {default: children = null, ...slotted} = {},
+) {
+    const slots: Record<string, any> = {}
+    for (const [key, value] of Object.entries(slotted)) {
+        const name = slotName(key)
+        slots[name] = value
+    }
+
+    const {result} = this
+    try {
+        const html = await renderJSX(
+            result,
+            jsx(Component, {...props, ...slots, children}),
+        )
+        return {html}
+    } catch (e) {
+        throwEnhancedErrorIfMdxComponent(e as Error, Component)
+        throw e
+    }
+}
+
+function throwEnhancedErrorIfMdxComponent(error: Error, Component: any) {
+    // if the exception is from an mdx component
+    // throw an error
+    if (Component[Symbol.for("mdx-component")]) {
+        // if it's an existing AstroError, we don't need to re-throw, keep the original hint
+        if (AstroError.is(error))
+            return // Mimic the fields of the internal `AstroError` class (not from `astro/errors`) to
+            // provide better title and hint for the error overlay
+        ;(error as any).title = error.name
+        ;(error as any).hint =
+            `This issue often occurs when your MDX component encounters runtime errors.`
+        throw error
+    }
+}
+
+const renderer: NamedSSRLoadedRendererValue = {
+    name: "astro:jsx",
+    check,
+    renderToStaticMarkup,
+}
+
+export default renderer
diff --git a/src/vitePlugin.ts b/src/vitePlugin.ts
new file mode 100644
index 0000000..df4433d
--- /dev/null
+++ b/src/vitePlugin.ts
@@ -0,0 +1,50 @@
+import {HTMLRenderer, parse} from "gemtext"
+import {pathToFileURL} from "url"
+import type {Plugin} from "vite"
+import {ext} from "./index.js"
+
+function transform(code: string, id: string) {
+    const result = parse(code)
+    const html = result.generate(HTMLRenderer)
+    return `
+import {
+    createComponent,
+    render,
+    renderComponent,
+    unescapeHTML,
+} from "astro/runtime/server/index.js";
+import { Fragment, jsx as h } from "astro/jsx-runtime";
+import Layout from "../layouts/Layout.astro";
+export const name = "TypstComponent";
+export const html = ${JSON.stringify(html)};
+export const frontmatter = undefined;
+export const file = ${JSON.stringify(id)};
+export const url = ${JSON.stringify(pathToFileURL(id))};
+export function compiledContent() {
+    return html;
+}
+export function getHeadings() {
+    return undefined;
+}
+export async function Content() {
+    const content = h(Fragment, {"set:html": html});
+    return h(Layout, {title: url, children: content});
+}
+export default Content;
+`
+}
+
+export default function gemtextVitePlugin(): Plugin {
+    // let server: ViteDevServer
+    return {
+        name: "astro-gemtext",
+        enforce: "pre",
+        transform(code, id) {
+            if (!id.endsWith(`.${ext}`)) return
+            return {
+                code: transform(code, id),
+                map: null,
+            }
+        },
+    }
+}