fix(cli): sanitize project argument newlines

packages/cli/src/lib/arg-parsing.ts

@@ -153,6 +153,26 @@ const ISSUE_SHORT_ID_MULTI_SEGMENT_PARTS = 3;
 /** Splits a string into lines on LF or CRLF boundaries. */
 const LINE_SPLIT_PATTERN = /\r?\n/;
 
+/**
+ * Return the first non-blank line of `arg`, trimmed, or `""` if every line is
+ * blank.
+ *
+ * A bare `.trim()` only strips leading/trailing whitespace, so multi-line input
+ * (command substitution that captured extra output, a value with an appended
+ * note, or several newline-separated values — common from AI agents) keeps an
+ * internal newline that later fails `validateResourceId` with a cryptic
+ * "contains a newline" error (CLI-1G1, CLI-1RA). Slugs and identifiers are
+ * always single-line tokens, so the first non-blank line is the intended value.
+ */
+function firstNonBlankLine(arg: string): string {
+  return (
+    arg
+      .split(LINE_SPLIT_PATTERN)
+      .map((line) => line.trim())
+      .find((line) => line.length > 0) ?? ""
+  );
+}
+
 /** Splits a string on any run of whitespace. */
 const WHITESPACE_SPLIT_PATTERN = /\s+/;
 
@@ -900,12 +920,13 @@ export function parseOrgProjectArg(
   arg: string | undefined,
   options: { multi?: boolean } = {},
 ): ParsedOrgProject {
-  if (!arg || arg.trim() === "") {
+  // Keep only the first non-blank line: agents often pass targets with
+  // appended output or notes after a newline (CLI-1RA).
+  const trimmed = arg ? firstNonBlankLine(arg) : "";
+  if (!trimmed) {
     return { type: "auto-detect" };
   }
 
-  const trimmed = arg.trim();
-
   // URL detection — extract org/project from Sentry web URLs
   const urlParsed = parseSentryUrl(trimmed);
   if (urlParsed) {
@@ -1412,11 +1433,7 @@ export function parseIssueArg(arg: string): ParsedIssueArg {
   // lines would produce garbage, so we keep only the first line.
   // Splitting on `\n` (a control char) never breaks project display names with
   // spaces (#1116), since those are rejected as control chars anyway.
-  const input =
-    arg
-      .split(LINE_SPLIT_PATTERN)
-      .map((line) => line.trim())
-      .find((line) => line.length > 0) ?? "";
+  const input = firstNonBlankLine(arg);
 
   if (!input) {
     throw new ValidationError(

packages/cli/test/lib/arg-parsing.test.ts

@@ -1517,6 +1517,45 @@ describe("parseOrgProjectArg: injection hardening", () => {
   });
 });
 
+// Agents pass targets with appended output/notes after a newline. A bare
+// trim() left the internal newline, which threw "Invalid project slug:
+// contains a newline" (CLI-1RA). Targets are single-line, so keep line one.
+describe("parseOrgProjectArg: multi-line input (CLI-1RA)", () => {
+  test("keeps the first line of an org/project target", () => {
+    expect(parseOrgProjectArg("sentry/cli\nextra")).toEqual({
+      type: "explicit",
+      org: "sentry",
+      project: "cli",
+    });
+  });
+
+  test("keeps the first line of a bare project target", () => {
+    expect(parseOrgProjectArg("cli\nsome note")).toEqual({
+      type: "project-search",
+      projectSlug: "cli",
+    });
+  });
+
+  test("skips leading blank lines and handles CRLF", () => {
+    expect(parseOrgProjectArg("\r\n  \r\nsentry/cli\r\nextra\r\n")).toEqual({
+      type: "explicit",
+      org: "sentry",
+      project: "cli",
+    });
+  });
+
+  test("keeps the first line of an org-all target", () => {
+    expect(parseOrgProjectArg("sentry/\nextra")).toEqual({
+      type: "org-all",
+      org: "sentry",
+    });
+  });
+
+  test("all-blank multi-line input auto-detects", () => {
+    expect(parseOrgProjectArg("  \n \r\n  ")).toEqual({ type: "auto-detect" });
+  });
+});
+
 describe("parseIssueArg: injection hardening", () => {
   test("rejects query injection in issue arg", () => {
     expect(() => parseIssueArg("CLI-G?query=foo")).toThrow(ValidationError);