func DiskImageDiffSuppress()

in tpgtools/ignored_handwritten/disk_utils.go [24:107]
46 lines of code
14 McCabe index (conditional complexity)

func DiskImageDiffSuppress(_, old, new string, _ *schema.ResourceData) bool {
	// Understand that this function solves a messy problem ("how do we tell if the diff between two images
	// is 'ForceNew-worthy', without making a network call?") in the best way we can: through a series of special
	// cases and regexes.  If you find yourself here because you are trying to add a new special case,
	// you are probably looking for the diskImageFamilyEquals function and its subfunctions.
	// In order to keep this maintainable, we need to ensure that the positive and negative examples
	// in resource_compute_disk_test.go are as complete as possible.

	// 'old' is read from the API.
	// It always has the format 'https://www.googleapis.com/compute/v1/projects/(%s)/global/images/(%s)'
	matches := resolveImageLink.FindStringSubmatch(old)
	if matches == nil {
		// Image read from the API doesn't have the expected format. In practice, it should never happen
		return false
	}
	oldProject := matches[1]
	oldName := matches[2]

	// Partial or full self link family
	if resolveImageProjectFamily.MatchString(new) {
		// Value matches pattern "projects/{project}/global/images/family/{family-name}$"
		matches := resolveImageProjectFamily.FindStringSubmatch(new)
		newProject := matches[1]
		newFamilyName := matches[2]

		return diskImageProjectNameEquals(oldProject, newProject) && diskImageFamilyEquals(oldName, newFamilyName)
	}

	// Partial or full self link image
	if resolveImageProjectImage.MatchString(new) {
		// Value matches pattern "projects/{project}/global/images/{image-name}$"
		matches := resolveImageProjectImage.FindStringSubmatch(new)
		newProject := matches[1]
		newImageName := matches[2]

		return diskImageProjectNameEquals(oldProject, newProject) && diskImageEquals(oldName, newImageName)
	}

	// Partial link without project family
	if resolveImageGlobalFamily.MatchString(new) {
		// Value is "global/images/family/{family-name}"
		matches := resolveImageGlobalFamily.FindStringSubmatch(new)
		familyName := matches[1]

		return diskImageFamilyEquals(oldName, familyName)
	}

	// Partial link without project image
	if resolveImageGlobalImage.MatchString(new) {
		// Value is "global/images/{image-name}"
		matches := resolveImageGlobalImage.FindStringSubmatch(new)
		imageName := matches[1]

		return diskImageEquals(oldName, imageName)
	}

	// Family shorthand
	if resolveImageFamilyFamily.MatchString(new) {
		// Value is "family/{family-name}"
		matches := resolveImageFamilyFamily.FindStringSubmatch(new)
		familyName := matches[1]

		return diskImageFamilyEquals(oldName, familyName)
	}

	// Shorthand for image or family
	if resolveImageProjectImageShorthand.MatchString(new) {
		// Value is "{project}/{image-name}" or "{project}/{family-name}"
		matches := resolveImageProjectImageShorthand.FindStringSubmatch(new)
		newProject := matches[1]
		newName := matches[2]

		return diskImageProjectNameEquals(oldProject, newProject) &&
			(diskImageEquals(oldName, newName) || diskImageFamilyEquals(oldName, newName))
	}

	// Image or family only
	if diskImageEquals(oldName, new) || diskImageFamilyEquals(oldName, new) {
		// Value is "{image-name}" or "{family-name}"
		return true
	}

	return false
}