private async validateReplacementConfig()

in src/videofx/VideoFxProcessor.ts [419:478]
52 lines of code
16 McCabe index (conditional complexity)

  private async validateReplacementConfig(config: VideoFxConfig): Promise<void> {
    if (
      config.backgroundReplacement.backgroundImageURL &&
      config.backgroundReplacement.defaultColor
    ) {
      throw new Error(
        `Invalid VideoFx configuration: Background Replacement can not have both an ` +
          `image URL and default color`
      );
    }
    if (
      !config.backgroundReplacement.backgroundImageURL &&
      !config.backgroundReplacement.defaultColor
    ) {
      throw new Error(
        `Invalid VideoFx configuration: Background Replacement image URL and default ` +
          `can not both be null/undefined`
      );
    }

    // Confirm that the image properly loads
    try {
      if (config.backgroundReplacement.backgroundImageURL) {
        await this.canvasOpsManager.loadImage(config.backgroundReplacement.backgroundImageURL);
      }
    } catch (error) {
      this.logger.error(error.toString());
      throw new Error(`Invalid VideoFx configuration: backgroundImageURL failed to load`);
    }

    const defaultColor = config.backgroundReplacement.defaultColor;
    // Confirm that defaultColor is a valid color for fillStyle. We support black by default.
    if (
      defaultColor &&
      defaultColor !== 'black' &&
      defaultColor !== '#000000' &&
      defaultColor !== '#000'
    ) {
      // First validate hexadecimal color code
      if (defaultColor.includes('#')) {
        const hexRegex = new RegExp(/^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$/);
        if (!hexRegex.test(defaultColor)) {
          throw new Error(
            `Invalid hexadecimal color code for default replacement ` +
              `background: ${defaultColor}`
          );
        }
      }
      const testColorCanvas = document.createElement('canvas');
      const testColorCtx = testColorCanvas.getContext('2d');
      // fillStyle is #000000 black by default
      const prevFillStyle = testColorCtx.fillStyle;
      testColorCtx.fillStyle = defaultColor;
      // fillStyle will not change after assignment if invalid value is used
      /* istanbul ignore next */
      if (testColorCtx.fillStyle === prevFillStyle) {
        throw new Error(`Invalid color for default replacement background: ${defaultColor}`);
      }
    }
  }