Method _verifyNoOptionValueCollisions

src/cdk/listbox/listbox.ts:978–1012

Verifies that no two options represent the same value under the compareWith function.

()

  /** Verifies that no two options represent the same value under the compareWith function. */
  private _verifyNoOptionValueCollisions() {
    this.options.changes.pipe(startWith(this.options), takeUntil(this.destroyed)).subscribe(() => {
      const isEqual = this.compareWith ?? Object.is;
      for (let i = 0; i < this.options.length; i++) {
        const option = this.options.get(i)!;
        let duplicate: CdkOption<T> | null = null;
        for (let j = i + 1; j < this.options.length; j++) {
          const other = this.options.get(j)!;
          if (isEqual(option.value, other.value)) {
            duplicate = other;
            break;
          }
        }
        if (duplicate) {
          // TODO(mmalerba): Link to docs about this.
          if (this.compareWith) {
            console.warn(
              `Found multiple CdkOption representing the same value under the given compareWith function`,
              {
                option1: option.element,
                option2: duplicate.element,
                compareWith: this.compareWith,
              },
            );
          } else {
            console.warn(`Found multiple CdkOption with the same value`, {
              option1: option.element,
              option2: duplicate.element,
            });
          }
          return;
        }
      }
    });
  }

  /** Verifies that the option values are valid. */
  private _verifyOptionValues() {