Extract from Norganizer

1 files changed, 45 insertions, 0 deletions

diff --git a/Tests/NorgKeyboardToolbarTests/LineScannerTests.swift b/Tests/NorgKeyboardToolbarTests/LineScannerTests.swift
new file mode 100644
index 0000000..17b9cb0
--- /dev/null
+++ b/Tests/NorgKeyboardToolbarTests/LineScannerTests.swift
@@ -0,0 +1,45 @@
+import Testing
+
+@testable import NorgKeyboardToolbar
+
+struct LineScannerTests {
+
+  @Test func lineStartFindsBeginningOfCurrentLine() {
+    let chars = Array("first\nsecond")
+    // Cursor inside "second" (offset 9 -> the 'o').
+    #expect(LineScanner.lineStart(in: chars, at: 9) == 6)
+  }
+
+  @Test func lineStartAtBufferStartIsZero() {
+    let chars = Array("hello")
+    #expect(LineScanner.lineStart(in: chars, at: 3) == 0)
+  }
+
+  @Test func lineStartJustAfterNewlineIsTheNewLine() {
+    let chars = Array("a\nb")
+    // Offset 2 sits at 'b', whose line starts right after the newline.
+    #expect(LineScanner.lineStart(in: chars, at: 2) == 2)
+  }
+
+  @Test func lineEndFindsNextNewline() {
+    let chars = Array("first\nsecond")
+    #expect(LineScanner.lineEnd(in: chars, at: 2) == 5)
+  }
+
+  @Test func lineEndAtLastLineIsBufferCount() {
+    let chars = Array("first\nsecond")
+    #expect(LineScanner.lineEnd(in: chars, at: 8) == chars.count)
+  }
+
+  @Test func lineEndOnNewlineStaysPut() {
+    let chars = Array("a\nb")
+    // Offset 1 is the newline itself.
+    #expect(LineScanner.lineEnd(in: chars, at: 1) == 1)
+  }
+
+  @Test func handlesEmptyBuffer() {
+    let chars: [Character] = []
+    #expect(LineScanner.lineStart(in: chars, at: 0) == 0)
+    #expect(LineScanner.lineEnd(in: chars, at: 0) == 0)
+  }
+}