What is left to refund on each order is an account of its own: the sale adds to it, a refund takes from it, and it never goes below 0. A refund is held while it waits for approval
examples/refunds/refunds.book, as chobo doc writes it. Each account keeps a balance: what came in, less what went out. Every transfer keeps the bounds of the accounts: one that would break a bound is refused with the name the book gives that bound, and nothing of it moves. A transfer either moves at once (do), or first holds what it moves (hold); a hold is then posted (post, all of it or part), voided (void), or expires.
| Account | One for each | Unit | Bounds | What it is |
|---|---|---|---|---|
refundable | order | USD | at least 0.00; a transfer that would go below is refused with refund_exceeds_sale | what is left to refund on the order |
sales | one account | USD | outside the book: no bounds, and it may go below 0 | |
refunded | one account | USD | outside the book: no bounds, and it may go below 0 |
A box is an account, and an arrow a move of a transfer. A rounded, dashed box is an account outside the book, which has no bounds. A dashed arrow belongs to a transfer that holds first, and moves when the hold is posted.
amount from sales to refundable(order).order. The same call again does nothing, and answers done_before; one that differs only in amount is refused with key_conflict.do).| Operation | May be refused with | When |
|---|---|---|
sale.do | key_conflict | a call with the same order and other arguments came before |
1 sale.do(order: order-1, amount: 0.01) done 2 sale.do(order: order-1, amount: 0.02) refused: key_conflict
held while it waits for approval: posted when it is approved, voided when it is turned down
amount from refundable(order) to refunded.request. The same call again does nothing, and answers done_before; one that differs only in order or amount is refused with key_conflict; holding again with the same key after the hold has ended answers done_before, and holds nothing.| The hold | post | void |
|---|---|---|
| held | posts it: the amounts given, or all of it, and the rest goes back; more than it holds is refused with over_hold; once 7 days have passed since it was held, refused with expired | voids it: what it holds goes back; once 7 days have passed since it was held, refused with expired |
| posted | done_before with the same amounts; refused with key_conflict with others | refused with already_posted |
| voided | refused with already_voided | done_before |
| expired | refused with expired | refused with expired |
| no hold with the key | refused with no_such_hold | refused with no_such_hold |
| Operation | May be refused with | When |
|---|---|---|
refund.hold | refund_exceeds_sale | refundable(order) would go below 0.00 |
refund.hold | key_conflict | a call with the same request and other arguments came before |
refund.hold | already_refused | a call with the same request was refused by a bound before; a key a bound refused stays refused, even once there is enough |
refund.post | key_conflict | the hold was posted before, for other amounts |
refund.post | already_voided | the hold is voided already |
refund.post | expired | the hold has expired |
refund.post | over_hold | more than the hold holds |
refund.post | no_such_hold | there is no hold with that request |
refund.void | already_posted | the hold is posted already |
refund.void | expired | the hold has expired |
refund.void | no_such_hold | there is no hold with that request |
1 refund.hold(request: request-1, order: order-2, amount: 0.01) refused: refund_exceeds_sale (move 1 takes 0.01 from refundable(order-2): posted 0.00, held out 0.00)
1 sale.do(order: order-1, amount: 0.01) done 2 refund.hold(request: request-2, order: order-1, amount: 0.01) done 3 refund.hold(request: request-2, order: order-1, amount: 0.02) refused: key_conflict
1 refund.hold(request: request-1, order: order-2, amount: 0.01) refused: refund_exceeds_sale (move 1 takes 0.01 from refundable(order-2): posted 0.00, held out 0.00) 2 refund.hold(request: request-1, order: order-2, amount: 0.01) refused: already_refused
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 refund.post(request: request-2) done 4 refund.post(request: request-2, amount: 0.01) refused: key_conflict
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 refund.void(request: request-2) done 4 refund.post(request: request-2) refused: already_voided
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 pass 7 days refund(request-2) expired 4 refund.post(request: request-2) refused: expired
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 refund.post(request: request-2, amount: 0.03) refused: over_hold
1 refund.post(request: request-1) refused: no_such_hold
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 refund.post(request: request-2) done 4 refund.void(request: request-2) refused: already_posted
1 sale.do(order: order-1, amount: 0.02) done 2 refund.hold(request: request-2, order: order-1, amount: 0.02) done 3 pass 7 days refund(request-2) expired 4 refund.void(request: request-2) refused: expired
1 refund.void(request: request-1) refused: no_such_hold
19 scenarios, which chobo scenarios makes from the book. Pick one and step through it: after each step come the balances and the holds it left, and on the chart the arrows of the transfers it called light up (red when refused).
| Account | Posted | Held out | Held in |
|---|
| Hold | State |
|---|