1 files changed, 53 insertions, 0 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index b64b62d7..8c643be6 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -5841,6 +5841,17 @@ pub const Options = struct {
     /// not consulted at all (it never was — the file arm always won).
     file: ?[]const u8 = null,
     file_line: usize = 0,
+    /// argv NAMED SOMETHING THAT IS NOT THERE — no file, no directory, nothing
+    /// `look.resolve` could make a target of. The word as the human typed it,
+    /// and it boots one `+Errors` pane saying so.
+    ///
+    /// A launch is not a failure worth refusing. `pardes nosuchfile` used to
+    /// return `BadArgs` out of `main`, which std prints as `error: BadArgs`
+    /// with a return trace under it — indistinguishable from a crash for a
+    /// typo, and it left the human with no editor at all. Outranked by `file`
+    /// for the same reason `file` outranks `shells`: only one of them can name
+    /// the boot layout, and they are never both set.
+    missing_path: ?[]const u8 = null,
     tty_toggle: u21 = config.tty_toggle_default,
     /// load a dump of another instance instead of spawning shells (acme -l)
     load_path: ?[]const u8 = null,
@@ -6322,6 +6333,28 @@ pub const Pardes = struct {
             p.ncol = 1;
             p.col_n[0] = 1;
             p.col_terms[0][0] = 0;
+        } else if (opts.missing_path) |word| {
+            // ARGV NAMED NOTHING. `+Errors` and not the message row, because a
+            // launch has no pane to put a message row on yet — and because
+            // this is exactly what acme's `+Errors` is: output from the
+            // program rather than from a word anybody clicked (output_pane
+            // `Origin.errors`). Filling the window with it makes the answer
+            // unmissable, which a one-line message under a shell prompt is
+            // not.
+            //
+            // The word AS TYPED, not a resolved path: there is nothing to
+            // resolve, and `pardes ~/notes/tdoo.md` wants to see its own typo
+            // back rather than an absolute path built around it.
+            const content = try std.fmt.allocPrint(
+                gpa,
+                "file or directory not found\n\n\t{s}\n",
+                .{word},
+            );
+            errdefer gpa.free(content);
+            _ = try output_pane.open(p, 0, "", .errors, "", content);
+            p.ncol = 1;
+            p.col_n[0] = 1;
+            p.col_terms[0][0] = 0;
         } else if (comptime platform == .esp32p4) {
             // BARE METAL BOOTS AN EMPTY OUTPUT BUFFER, and a shell is not a layout preference
             // here but an impossibility: there is no operating system under this, so there is
@@ -16419,6 +16452,26 @@ test "Esc alternates between two panes of the SAME kind" {
     }
 }
 
+test "argv naming nothing boots an errors pane rather than failing the launch" {
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{ .cols = 80, .rows = 24, .missing_path = "notes/tdoo.md" });
+    defer p.deinit();
+    p.update(.{ .resize = .{ .cols = 80, .rows = 24 } });
+
+    // One pane, filling the window, and it is an OUTPUT pane rather than the
+    // shell a bare `pardes` boots: the answer is the whole screen.
+    try std.testing.expectEqual(@as(u8, 1), p.ncol);
+    try std.testing.expectEqual(@as(usize, 1), p.col_n[0]);
+    const pane = p.panes[0].?;
+    try std.testing.expect(!pane.isTerminal());
+    const f = pane.file.?;
+    try std.testing.expectEqual(output_pane.Origin.errors, f.output.?.from);
+    // ...and it says what happened AND what was asked for. The word as typed,
+    // which is the half a bare "not found" leaves out.
+    try std.testing.expect(std.mem.indexOf(u8, f.content, "not found") != null);
+    try std.testing.expect(std.mem.indexOf(u8, f.content, "notes/tdoo.md") != null);
+}
+
 test "Esc back into a tty leaves its view at the prompt" {
     if (platform == .web) return;
     const gpa = std.testing.allocator;