Component generator has inconsistent behaviors

[ZheSun88]

This issue occurs when generates code for vaadin-time-picker:

Behavior 1:
when i am using only "vaadin-time-picker": "1.0.0-beta1" in the bower.json, we will get two generated java files successfully, in the GeneratedVaadinTimePickerTextField.java file, we can see the signature:

public abstract class GeneratedVaadinTimePickerTextField<R extends GeneratedVaadinTimePickerTextField<R, T>, T>
        extends AbstractSinglePropertyField<R, T> implements HasStyle {

Behavior 2:
if i am adding "vaadin-time-picker": "1.0.0-beta1" to bower.json with updated webcomponent version (will list the bower file next), we will get a compilation failure on the generation, the signature of GeneratedVaadinTimePickerTextField.java is

public abstract class GeneratedVaadinTimePickerTextField<R extends GeneratedVaadinTimePickerTextField<R>>
        extends GeneratedVaadinTextField<R> implements HasStyle {

and there is not import for the GeneratedVaadinTextField and the usage is wrong because the parent should take two parameters like GeneratedVaadinTextField<R, T>

further investigation on the next thread

[ZheSun88]

the bower.json file used for the 2nd case:

    "vaadin-text-field": "2.1.0-beta2",
    "vaadin-time-picker": "1.0.0-beta1"

some investigations:
in the 2nd case, the webcomponent-api-analyzer cannot provide a correct .json file for the vaadin-time-picker-text-field and from the log, it shows

 Element: vaadin-time-picker-text-field baseUrl: vaadin-time-picker/src/vaadin-time-picker-text-field.html extends: Vaadin.TextFieldElement, template: false
[INFO]     behaviors:
[INFO]     kinds: class,element,polymer-element
[INFO]     identifiers: Vaadin.TimePickerTextFieldElement,vaadin-time-picker-text-field
[INFO]     mixins:
[INFO] Generating JSON for vaadin-time-picker-text-field
[INFO]     Wrote 0 properties out of 23
[INFO]     Wrote 0 methods out of 22
[INFO]     Wrote 0 events out of 1

[ZheSun88]

i am not sure which is the correct behavior, it looks both cases have some incorrect part:

for case 1): the vaadin-time-picker-text-field.html has an import for text-field, so it can be understood as the parent https://github.com/vaadin/vaadin-time-picker/blob/master/src/vaadin-time-picker-text-field.html#L7 , so the generated class should extends from TextField

for case 2): the generated file is using wrong signature and without correct import

possibly related to https://github.com/vaadin/flow/blob/master/flow-components-parent/flow-webcomponent-api-analyzer/lib/js/element-json-transform.js#L142

when there is only one dependency, the parentClassDate returns undefined. After add vaadin-text-field dependency to bower.json, it returns vaadin-text-field.