From bfae2b12e00843202315f0b55a8d9eeb2fd5e1bd Mon Sep 17 00:00:00 2001
From: Rene Saarsoo <nene@triin.net>
Date: Sat, 26 Dec 2020 17:31:01 +0200
Subject: [PATCH] Detect overlapping comments

---
 src/parser/parser.test.ts | 26 ++++++++++++++++++++++++++
 src/parser/validate.ts    | 10 +++++++---
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/parser/parser.test.ts b/src/parser/parser.test.ts
index c1a9894..82ba192 100644
--- a/src/parser/parser.test.ts
+++ b/src/parser/parser.test.ts
@@ -664,4 +664,30 @@ Interval: 2:00 90%
 `),
     ).toThrowErrorMatchingInlineSnapshot(`"Negative comment offset is larger than interval length at line 5 char 5"`);
   });
+
+  it("throws error when comment offset is the same as another comment offset", () => {
+    expect(() =>
+      parse(`
+Name: My Workout
+Interval: 2:00 90%
+  @ 0:00 First comment
+  @ 1:00 Comment
+  @ 1:00 Overlapping comment
+  @ 1:50 Last comment
+`),
+    ).toThrowErrorMatchingInlineSnapshot(`"Comment overlaps previous comment at line 6 char 5"`);
+  });
+
+  it("throws error when comment offset is greater than next comment offset", () => {
+    expect(() =>
+      parse(`
+Name: My Workout
+Interval: 2:00 90%
+  @ 0:00 First comment
+  @ 1:20 Comment
+  @ 1:00 Misplaced comment
+  @ 1:50 Last comment
+`),
+    ).toThrowErrorMatchingInlineSnapshot(`"Comment overlaps previous comment at line 6 char 5"`);
+  });
 });
diff --git a/src/parser/validate.ts b/src/parser/validate.ts
index 0830450..2902ae7 100644
--- a/src/parser/validate.ts
+++ b/src/parser/validate.ts
@@ -1,14 +1,18 @@
 import { Workout, Interval } from "../ast";
 import { ValidationError } from "./ValidationError";
 
-const validateCommentOffsets = (interval: Interval) => {
-  for (const comment of interval.comments) {
-    if (comment.offset.seconds >= interval.duration.seconds) {
+const validateCommentOffsets = ({ comments, duration }: Interval) => {
+  for (let i = 0; i < comments.length; i++) {
+    const comment = comments[i];
+    if (comment.offset.seconds >= duration.seconds) {
       throw new ValidationError(`Comment offset is larger than interval length`, comment.loc);
     }
     if (comment.offset.seconds < 0) {
       throw new ValidationError(`Negative comment offset is larger than interval length`, comment.loc);
     }
+    if (i > 0 && comment.offset.seconds <= comments[i - 1].offset.seconds) {
+      throw new ValidationError(`Comment overlaps previous comment`, comment.loc);
+    }
   }
 };