From 9d66b3472c2751339989802aafd9d97b9386a5d3 Mon Sep 17 00:00:00 2001
From: Turiiya <34311583+ttytm@users.noreply.github.com>
Date: Sat, 16 Mar 2024 10:21:02 +0100
Subject: [PATCH] fmt: insert auto imports after shebang (#21038)

---
 vlib/v/fmt/fmt.v                                      | 11 ++++++++---
 vlib/v/fmt/tests/import_auto_with_shebang_expected.vv |  5 +++++
 vlib/v/fmt/tests/import_auto_with_shebang_input.vv    |  3 +++
 3 files changed, 16 insertions(+), 3 deletions(-)
 create mode 100644 vlib/v/fmt/tests/import_auto_with_shebang_expected.vv
 create mode 100644 vlib/v/fmt/tests/import_auto_with_shebang_input.vv

diff --git a/vlib/v/fmt/fmt.v b/vlib/v/fmt/fmt.v
index ec0c904ef7b855..77a97d122297f8 100644
--- a/vlib/v/fmt/fmt.v
+++ b/vlib/v/fmt/fmt.v
@@ -97,9 +97,14 @@ pub fn fmt(file ast.File, mut table ast.Table, pref_ &pref.Preferences, is_debug
 		}
 		return res
 	}
-	source_for_imports := res[..f.import_pos] + f.out_imports.str()
-	source_after_imports := res[f.import_pos..]
-	return source_for_imports + source_after_imports
+	mut import_start_pos := f.import_pos
+	if stmt := file.stmts[1] {
+		if stmt is ast.ExprStmt && stmt.expr is ast.Comment
+			&& (stmt.expr as ast.Comment).text.starts_with('#!') {
+			import_start_pos = stmt.pos.len
+		}
+	}
+	return res[..import_start_pos] + f.out_imports.str() + res[import_start_pos..]
 }
 
 pub fn (mut f Fmt) process_file_imports(file &ast.File) {
diff --git a/vlib/v/fmt/tests/import_auto_with_shebang_expected.vv b/vlib/v/fmt/tests/import_auto_with_shebang_expected.vv
new file mode 100644
index 00000000000000..93d4fc265e5857
--- /dev/null
+++ b/vlib/v/fmt/tests/import_auto_with_shebang_expected.vv
@@ -0,0 +1,5 @@
+#!/usr/bin/env -S v
+
+import os
+
+os.join_path('a', 'b', 'c')
diff --git a/vlib/v/fmt/tests/import_auto_with_shebang_input.vv b/vlib/v/fmt/tests/import_auto_with_shebang_input.vv
new file mode 100644
index 00000000000000..2d302758b83efb
--- /dev/null
+++ b/vlib/v/fmt/tests/import_auto_with_shebang_input.vv
@@ -0,0 +1,3 @@
+#!/usr/bin/env -S v
+os.join_path('a','b','c')
+