From 5d886acb37ebce8340f1a240522ba320ae45103f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Vasseur?= <jerome.vasseur@thetribe.io>
Date: Mon, 29 Aug 2022 15:44:31 +0200
Subject: [PATCH] Handle template starting with empty line

---
 README.md     |  2 +-
 index.test.ts | 14 ++++++++++++++
 index.ts      |  2 +-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 844313e..48d0263 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,6 @@ indentation:
 - First it treats the start and end of the template to remove the lines
   that contains the backticks.
 - Then it removes the indentation of each line base on the indentation of the
-  first line.
+  first non-empty line.
 - Finaly, it indents strings that are passed into the placeholders based of the
   indentation preceding them.
diff --git a/index.test.ts b/index.test.ts
index 556c502..e8edb9b 100644
--- a/index.test.ts
+++ b/index.test.ts
@@ -20,6 +20,20 @@ test('It reindent placeholders', () => {
     `).toBe('<test>\n    test\n    value\n</test>');
 });
 
+test('It correctly detect indentation when first line is empty', () => {
+    expect(indent`
+
+        Test
+    `).toBe('\nTest');
+});
+
+test('It correctly detect indentation when last line is empty', () => {
+    expect(indent`
+        Test
+
+    `).toBe('Test\n');
+});
+
 test('Nested indent test', () => {
     const list = ['First', 'Second'];
 
diff --git a/index.ts b/index.ts
index c726a98..c8dc437 100644
--- a/index.ts
+++ b/index.ts
@@ -12,7 +12,7 @@ const indentTag = (strings: TemplateStringsArray, ... expressions: any[]) => {
     parts[strings.length - 1] = parts[parts.length - 1].replace(/\n[ \t]*$/, '');
 
     // Dedent using indent from first part
-    const indent = parts[0].match(/^[ \t]*/)![0];
+    const indent = parts[0].match(/^\n*([ \t]*)/)![1];
 
     const deindent = new RegExp(`(^|\n)${indent}`, 'g');