fix: treat property names as case-insensitive

ics/with-lowercase-properties.ics

@@ -0,0 +1,23 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Test//Test//EN
+BEGIN:VEVENT
+dtstart:20200101T100000Z
+dtend:20200101T110000Z
+uid:lowercase-past@test
+summary:Past event with lowercase properties
+END:VEVENT
+BEGIN:VEVENT
+dtstart:20300101T100000Z
+dtend:20300101T110000Z
+uid:lowercase-future@test
+summary:Future event with lowercase properties
+END:VEVENT
+BEGIN:VEVENT
+DTSTART:20200601T120000Z
+DTEND:20200601T130000Z
+UID:uppercase-past@test
+rrule:FREQ=YEARLY
+SUMMARY:Past recurring event with lowercase rrule
+END:VEVENT
+END:VCALENDAR

src/index.ts

@@ -45,9 +45,10 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
 
   function processLine(line: string): void {
     line = line.trim();
+    const lineUpper: string = line.toUpperCase();
 
     // --- BEGIN EVENT ---
-    if (line === "BEGIN:VEVENT") {
+    if (lineUpper === "BEGIN:VEVENT") {
       inEvent = true;
       eventStartIndex = findLineStartIndex(line);
       if (isDevRun) {
@@ -62,7 +63,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
     }
 
     // --- END EVENT ---
-    if (line === "END:VEVENT") {
+    if (lineUpper === "END:VEVENT") {
       const eventEndIndex: number = findLineEndIndex(line);
       if (isDevRun) {
         if (inEvent && keep && rruleKeep) {
@@ -91,7 +92,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
     }
 
     // --- PARSING ---
-    if (line.startsWith("SUMMARY")) {
+    if (lineUpper.startsWith("SUMMARY")) {
       const value: string | null = extractValue(line);
       if (isDevRun) {
         console.log("SUMMARY:", value);
@@ -100,7 +101,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
       return;
     }
 
-    if (line.startsWith("DTSTART")) {
+    if (lineUpper.startsWith("DTSTART")) {
       const value: string | null = extractValue(line);
       const dtStart: string | null = normalizeICSDateStr(value);
       if (isDevRun) {
@@ -125,7 +126,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
       return;
     }
 
-    if (line.startsWith("DTEND")) {
+    if (lineUpper.startsWith("DTEND")) {
       const value: string | null = extractValue(line);
       const dtEnd: string | null = normalizeICSDateStr(value);
       if (isDevRun) {
@@ -158,7 +159,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
       return;
     }
 
-    if (line.startsWith("RRULE")) {
+    if (lineUpper.startsWith("RRULE")) {
       const idx: number = line.indexOf("UNTIL=");
 
       keep = true;
@@ -187,7 +188,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
       return;
     }
 
-    if (line.startsWith("RECURRENCE-ID")) {
+    if (lineUpper.startsWith("RECURRENCE-ID")) {
       const value: string | null = extractValue(line);
       const dtRecurrence: string | null = normalizeICSDateStr(value);
       if (isDevRun) {
@@ -218,7 +219,7 @@ export const icsFilter = (content: string, now: Date, max?: Date): string => {
       return;
     }
 
-    if (line.startsWith("STATUS:CANCELLED")) {
+    if (lineUpper.startsWith("STATUS:CANCELLED")) {
       keep = false;
     }
   }

src/tests/lowercase-properties.test.ts

@@ -0,0 +1,17 @@
+import assert from "node:assert";
+import { readFileSync } from "node:fs";
+import { describe, test } from "node:test";
+
+import { icsFilter } from "../index.js";
+
+const content: string = readFileSync("./ics/with-lowercase-properties.ics", "utf-8");
+const now: Date = new Date();
+const filteredContent: string = icsFilter(content, now);
+
+describe("icsFilter on ics content with lowercase property names", () => {
+  test("should handle lowercase DTSTART, DTEND and RRULE", () => {
+    assert.ok(filteredContent.includes("lowercase-future@test"), "Future event with lowercase properties should be kept");
+    assert.ok(!filteredContent.includes("lowercase-past@test"), "Past event with lowercase properties should be filtered out");
+    assert.ok(filteredContent.includes("uppercase-past@test"), "Past recurring event with lowercase rrule should be kept");
+  });
+});