Add support for $# comment lines in parser

src/parse.test.ts

@@ -127,6 +127,38 @@ describe("parse", () => {
     expect(result.commands[0]!.expected).toEqual(["hi"])
   })
 
+  test("$# comment line is skipped", () => {
+    const result = parse("test.shout", "$# start the server\n$ echo hi\nhi\n")
+    expect(result.commands).toHaveLength(1)
+    expect(result.commands[0]!.command).toBe("echo hi")
+  })
+
+  test("$# comment between commands", () => {
+    const result = parse("test.shout", "$ echo one\none\n$# now do two\n$ echo two\ntwo\n")
+    expect(result.commands).toHaveLength(2)
+    expect(result.commands[0]!.expected).toEqual(["one"])
+    expect(result.commands[1]!.expected).toEqual(["two"])
+  })
+
+  test("$# comment with space after hash", () => {
+    const result = parse("test.shout", "$ # server setup\n$ echo hi\nhi\n")
+    expect(result.commands).toHaveLength(1)
+    expect(result.commands[0]!.command).toBe("echo hi")
+  })
+
+  test("$# comment as last line", () => {
+    const result = parse("test.shout", "$ echo hi\nhi\n$# done\n")
+    expect(result.commands).toHaveLength(1)
+    expect(result.commands[0]!.expected).toEqual(["hi"])
+  })
+
+  test("output after $# comment is ignored", () => {
+    const result = parse("test.shout", "$ echo hi\nhi\n$# comment\nstray line\n$ echo bye\nbye\n")
+    expect(result.commands).toHaveLength(2)
+    expect(result.commands[0]!.expected).toEqual(["hi"])
+    expect(result.commands[1]!.expected).toEqual(["bye"])
+  })
+
   test("no directives returns empty array", () => {
     const result = parse("test.shout", "$ echo hi\nhi\n")
     expect(result.directives).toEqual([])

src/parse.ts

@@ -32,6 +32,11 @@ function stripComment(line: string): string {
   return line
 }
 
+/** A line like "$# ..." or "$ # ..." — a comment, not a real command */
+export function isCommentLine(line: string): boolean {
+  return line.startsWith("$#") || (line.startsWith("$ ") && stripComment(line.slice(2)) === "")
+}
+
 function parseExitCode(lines: string[]): {
   lines: string[]
   exitCode: number | "*" | null
@@ -134,7 +139,18 @@ export function parse(path: string, content: string): ShoutFile {
       continue
     }
 
-    if (line.startsWith("\\$ ") && current) {
+    if (isCommentLine(line)) {
+      // Comment line like "$# ..." or "$ # ..." — finalize current and skip
+      seenCommand = true
+      if (current) {
+        const trimmed = trimTrailingEmpty(current.expected)
+        const { lines: expectedLines, exitCode } = parseExitCode(trimmed)
+        current.expected = trimTrailingEmpty(expectedLines)
+        current.exitCode = exitCode
+        commands.push(current)
+      }
+      current = null
+    } else if (line.startsWith("\\$ ") && current) {
       // Escaped dollar-space: literal expected output starting with "$ "
       current.expected.push(line.slice(1))
     } else if (line.startsWith("$ ")) {

src/update.ts

@@ -1,6 +1,7 @@
 import type { CommandResult } from "./run.ts"
 import type { ShoutFile } from "./parse.ts"
 import { matchOutput, matchLine } from "./match.ts"
+import { isCommentLine } from "./parse.ts"
 
 export function rewriteFile(
   file: ShoutFile,
@@ -15,7 +16,10 @@ export function rewriteFile(
   for (let i = 0; i < lines.length; i++) {
     const line = lines[i]!
 
-    if (line.startsWith("$ ") && !line.startsWith("\\$ ")) {
+    if (isCommentLine(line)) {
+      // Preserve comment lines as-is
+      output.push(line)
+    } else if (line.startsWith("$ ") && !line.startsWith("\\$ ")) {
       // Emit the command line as-is
       output.push(line)
 
@@ -28,7 +32,7 @@ export function rewriteFile(
 
       // Skip past old expected output lines in the original
       let j = i + 1
-      while (j < lines.length && !(lines[j]!.startsWith("$ ") && !lines[j]!.startsWith("\\$ "))) {
+      while (j < lines.length && !isCommentLine(lines[j]!) && !(lines[j]!.startsWith("$ ") && !lines[j]!.startsWith("\\$ "))) {
         j++
       }
       // Collect old expected lines (before trimming trailing blanks for separator)