When I set the fields:

Set several fields of the form from a table: the first column names the field, the second gives the value. Each row behaves like When I set the "<field>" field to "<value>".

Examples

When I set the fields:
When we set the fields:
And set the following fields:
When I set the following fields:
And we set the following fields:

Pattern

When(/^(I |we )*set the (?:following )?fields:$/, …)

Part of @webship-js/odoo-steps (github.com/webship/odoo-steps), a step pack for Webship-js 2.0.x.