bring back type sniffing

bin/help.ts

@@ -4,6 +4,7 @@
 
 import { commandPath } from "@/commands"
 import type { CommandOutput } from "@/shared/types"
+import { moduleExports, type ExportInfo } from "@/sniffer"
 import commands from "./commands"
 
 export default async function (cmd: string): Promise<CommandOutput> {
@@ -12,9 +13,14 @@ export default async function (cmd: string): Promise<CommandOutput> {
   const path = commandPath(cmd)
   if (!path) return await commands(cmd)
 
+  const signatures = await moduleExports(path)
+  const signature = signatures.default
+
   const code = (await Bun.file(path).text()).split("\n")
   let docs = []
 
+  docs.push(usage(cmd, signature), "")
+
   for (const line of code) {
     if (line.startsWith("///")) {
       docs.push("Runs in the browser.\n")
@@ -28,3 +34,18 @@ export default async function (cmd: string): Promise<CommandOutput> {
 
   return docs.join("\n")
 }
+
+function usage(cmd: string, signature?: ExportInfo) {
+  let out: string[] = [`usage: ${cmd}`]
+
+  if (signature?.kind === "function" && signature.signatures.length) {
+    const params = signature.signatures[0]!.params
+    for (const param of params) {
+      let desc = `${param.name}=`
+      desc += param.default ? `${param.default}` : `<${param.type}>`
+      out.push(desc)
+    }
+  }
+
+  return out.join(" ")
+}

src/commands.ts

@@ -82,7 +82,7 @@ export async function commandSource(name: string): Promise<string> {
 export async function loadCommandModule(cmd: string) {
   const path = commandPath(cmd)
   if (!path) return
-  return await importUrl(path + "?t+" + Date.now())
+  return await importUrl(path + "?t=" + Date.now())
 }
 
 let noseDirWatcher

src/dispatch.ts

@@ -8,7 +8,7 @@ import { send } from "./websocket"
 import { setState } from "./state"
 
 export async function dispatchMessage(ws: any, msg: Message) {
-  console.log("<- receive", msg)
+  // console.log("<- receive", msg)
   switch (msg.type) {
     case "input":
       await inputMessage(ws, msg); break

src/sniffer.ts

@@ -30,8 +30,7 @@ export type ExportInfo =
 
 let prevProgram: ts.Program | undefined
 
-
-export async function allExports(file: string): Promise<ExportInfo[]> {
+export async function moduleExports(file: string): Promise<Record<string, ExportInfo>> {
   const program = ts.createProgram([file], {
     target: ts.ScriptTarget.ESNext,
     module: ts.ModuleKind.ESNext,
@@ -48,7 +47,7 @@ export async function allExports(file: string): Promise<ExportInfo[]> {
   if (!sf) throw new SniffError(`File not found: ${file}`)
 
   const moduleSym = (sf as any).symbol as ts.Symbol | undefined
-  if (!moduleSym) return []
+  if (!moduleSym) return {}
 
   const exportSymbols = checker.getExportsOfModule(moduleSym)
   const result: ExportInfo[] = []
@@ -92,7 +91,9 @@ export async function allExports(file: string): Promise<ExportInfo[]> {
     }
   }
 
-  return result
+  return Object.fromEntries(
+    result.map(item => [item.name, item])
+  )
 }
 
 if (import.meta.main) {
@@ -101,5 +102,5 @@ if (import.meta.main) {
     console.error("usage: sniff <path>")
     process.exit(1)
   }
-  console.log(await allExports(path))
+  console.log(await moduleExports(path))
 }

src/websocket.ts

@@ -6,7 +6,7 @@ import type { Message } from "./shared/types"
 const wsConnections: any[] = []
 
 export function send(ws: any, msg: Message) {
-  console.log("-> send", msg)
+  // console.log("-> send", msg)
   ws.send(JSON.stringify(msg))
 }