End-to-End Testing Viewing an Existing ValueChart

[aaronpmishkin]

Implement end-to-end tests for viewing ValueCharts using the "View Existing ValueChart" button on the home page. These tests should include the cases:

1. Attempting to view a ValueChart that does not exist.
2. Attempting to a view a ValueChart that exists using an invalid password/name combination.
3. Successfully viewing a ValueChart with on only user (i.e. an individual ValueChart).
4. Successfully viewing a ValueChart with more than one user (i.e. a group ValueChart).

// The following are for testing if a user can change preferences (when only viewing a chart):

5. A user who is viewing a group ValueChart that they don't own is barred from changing the preferences
6. A user who is viewing a group ValueChart that they own is barred from changing the preferences.
7. A user who is viewing an individual ValueChart that they don't own is barred from changing the preferences in that ValueChart.
8. A user who is viewing an individual ValueChart that they own AND who is the current user in that chart CAN change the preferences.
9. A user who is viewing an individual ValueChart that they own BUT who is not the current user in that chart CANNOT change the preferences.

In the future, an explicit distinction will be added between the two types of charts - individual or group - that the user selects when they create the chart. This way, an individual chart will ALWAYS contain only the creator. Then, we will enable interactions for individual charts only. In that case, item 9 will no longer apply.

Include additional test cases as you see fit.