Replaced regex with a more strict version

src/command/metar/RunwayCommand.ts

@@ -13,7 +13,7 @@ import { ICommand } from "../metar";
 export class RunwayCommand implements ICommand {
   #genericRegex = /^(R\d{2}\w?\/)/;
   #runwayMaxRangeRegex = /^R(\d{2}\w?)\/(\d{4})V(\d{3,4})([UDN])?(FT)?/;
-  #runwayRegex = /^R(\d{2}\w?)\/([MP])?(\d{4})([UDN])?(FT)?(\/([UDN]))?$/;
+  #runwayRegex = /R(\d{2}\w?)\/([MP])?(\d{4})(?:([UDN])|(FT)(?:\/([UDN]))?)$/;
   #runwayDepositRegex = /^R(\d{2}\w?)\/([/\d])([/\d])(\/\/|\d{2})(\/\/|\d{2})$/;
 
   canParse(input: string): boolean {
@@ -43,9 +43,10 @@ export class RunwayCommand implements ICommand {
 
       const indicator = matches[2] ? as(matches[2], ValueIndicator) : undefined;
       const trend = (() => {
+        if (matches[6]) return as(matches[6], RunwayInfoTrend);
         if (matches[4]) return as(matches[4], RunwayInfoTrend);
-        if (matches[7]) return as(matches[7], RunwayInfoTrend);
       })();
+
       const unit = matches[5]
         ? as(matches[5], RunwayInfoUnit)
         : RunwayInfoUnit.Meters;

tests/command/metar/RunwayCommand.test.ts

@@ -205,4 +205,27 @@ describe("RunwayCommand", () => {
       });
     });
   })();
+
+  (() => {
+    const code = "R36/4000FT/D"; // runway info north america style
+    const metar = { runwaysInfo: [] } as unknown as IMetar;
+
+    describe(code, () => {
+      test("canParse", () => {
+        expect(command.canParse(code)).toBe(true);
+      });
+
+      test("parse", () => {
+        command.execute(metar, code);
+
+        expect(metar.runwaysInfo).toHaveLength(1);
+        expect(metar.runwaysInfo[0]).toEqual({
+          name: "36",
+          minRange: 4000,
+          unit: RunwayInfoUnit.Feet,
+          trend: RunwayInfoTrend.Decreasing,
+        });
+      });
+    });
+  })();
 });