begin-tx
Use begin-tx to begin a new transaction with an optional name.
This function is used to create tests that you want to execute using the Pact REPL.
In most cases, you include this function in .repl files that test specific application features and failure scenarios.
Within the context of a transaction, you can set environment data, load modules, and execute functions.
To complete the transaction, use the commit-tx function. The commit-tx function signals the end of a transaction block and can be followed by additional begin-tx and commit-tx blocks.
Basic syntax
To begin a transaction without a name, use the following syntax:
(begin-tx)
To begin a transaction with a specific name, use the following syntax:
(begin-tx name)
Arguments
Use the following argument to specify an optional name for the transaction when using the begin-tx Pact function.
| Argument | Type | Description |
|---|---|---|
name | string | Specifies the name of the transaction (optional). |
Return value
The begin-tx function returns a string indicating the transaction identifier and the optional name (if provided).
Examples
The following example demonstrates how to use the begin-tx function to begin a new transaction without a name:
pact> (begin-tx)
"Begin Tx 0"
The following example demonstrates how to use the begin-tx function to begin a new transaction with a specific name:
pact> (begin-tx "load module")
"Begin Tx 0: load module"
You can write an empty transaction as a placeholder for the logic to test specific function or failure scenarios. For example, to create a placeholder for the logic that defines a namespace:
(begin-tx "Define a namespace called 'election")
(commit-tx)