None colour from API (#1063)

apps/server/src/utils/__tests__/coerceType.test.ts

@@ -18,6 +18,13 @@ describe('parses a colour string that is', () => {
   it('not a string', () => {
     expect(() => coerceColour(5)).toThrowError(Error('Invalid colour value received'));
   });
+  it('undefinde and null are not valid', () => {
+    expect(() => coerceColour(null)).toThrowError(Error('Invalid colour value received'));
+    expect(() => coerceColour(undefined)).toThrowError(Error('Invalid colour value received'));
+  });
+  it('empty string is allowed', () => {
+    expect(coerceColour('')).toBe('');
+  });
 });
 
 describe('match a string to an enum that is', () => {

apps/server/src/utils/coerceType.ts

@@ -90,7 +90,12 @@ export function coerceColour(value: unknown): string {
     if (!isColourHex(lowerCaseValue)) {
       throw new Error('Invalid hex colour received');
     }
-  } else if (!(lowerCaseValue in cssColours)) {
+    return lowerCaseValue;
+  }
+  if (lowerCaseValue === '') {
+    return lowerCaseValue; // None colour the same as the UI 'Ø' button
+  }
+  if (!(lowerCaseValue in cssColours)) {
     throw new Error('Invalid colour name received');
   }
   return lowerCaseValue;