Refactor astro export map, add source-map-support (#161)

* fix: add svelte plugin for esbuild, remove precompiled svelte components

* refactor: public export map, public types

* feat: add source-map-support to common code paths

* chore: move new "exports" to "imports" map, add internal types

* Include outPath in error logging for bad load status, and drop error stack (#163)

* Include outPath in the error logging for bad load status

* Discard error stack since it seems not useful

* feat: improve build error logging

* refactor: use object param for writeResult

Co-authored-by: Kevin (Kun) "Kassimo" Qian <kevinkassimo@gmail.com>

scripts/utils/svelte-plugin.js

@@ -0,0 +1,60 @@
+// @ts-nocheck
+import { compile } from 'svelte/compiler';
+import { relative, isAbsolute, join, dirname } from 'path';
+import { promises as fs } from 'fs';
+
+const convertMessage = ({ message, start, end, filename, frame }) => ({
+    text: message,
+    location: start && end && {
+        file: filename,
+        line: start.line,
+        column: start.column,
+        length: start.line === end.line ? end.column - start.column : 0,
+        lineText: frame,
+    },
+})
+
+const handleLoad = async (args, generate) => {
+    const { path } = args;
+    const source = await fs.readFile(path, 'utf8');
+    const filename = relative(process.cwd(), path)
+
+    try {
+        let compileOptions = { css: false, generate, hydratable: true };
+
+        let { js, warnings } = compile(source, { ...compileOptions, filename })
+        let contents = js.code + `\n//# sourceMappingURL=` + js.map.toUrl()
+
+        return { loader: 'js', contents, resolveDir: dirname(path), warnings: warnings.map(w => convertMessage(w)) };
+    } catch (e) {
+        return { errors: [convertMessage(e)] }
+    }
+}
+
+export default function sveltePlugin() {
+    return {
+        name: 'svelte-esbuild',
+        setup(build) {
+                build.onResolve({ filter: /\.svelte$/ }, args => {
+                    let path = args.path.replace(/\.(?:client|server)/, '');
+                    path = isAbsolute(path) ? path : join(args.resolveDir, path)
+                    
+                    if (/\.client\.svelte$/.test(args.path)) {
+                        return {
+                            path,
+                            namespace: 'svelte:client',
+                        }
+                    }
+
+                    if (/\.server\.svelte$/.test(args.path)) {
+                        return {
+                            path,
+                            namespace: 'svelte:server',
+                        }
+                    }
+                });
+            build.onLoad({ filter: /.*/, namespace: 'svelte:client' }, (args) => handleLoad(args, 'dom'))
+            build.onLoad({ filter: /.*/, namespace: 'svelte:server' }, (args) => handleLoad(args, 'ssr'))
+        },
+    }
+}