jest-test-utils

Utility functions for use in tests using jest.

Installation

npm install --save-dev jest-test-utils

Usage

Setup jest

Add this to your jest config to extend jest expect with SQL statement matchers:

{
    "setupFilesAfterEnv": ["node_modules/jest-test-utils/dist/jest/sqlStatementMatchers.js"]
}

SQL statement matchers

function	description
toSelectFromTable	Verify that the sql statement selects from the specified table. Pass { distinct: true } to verify a SELECT DISTINCT statement.
toReplaceIntoTable	Verify that the sql statement replaces into the specified table.
toInsertIntoTable	Verify that the sql statement inserts into the specified table. In the optional options object you can specify an OR action, the columns in the correct order to be set, and columns used in an ON CONFLICT clause.
toUpdateTable	Verify that the sql statement updates the specified table.
toDeleteFromTable	Verify that the sql statement deletes from the specified table.
toJoinTable	Verify that the sql statement joins another table.
toSelectAllPropertiesOf	Verify that the sql statement selects all the columns of the specified DTO object.
toSetColumn	Verify that the sql statement sets the value of the specified column.
toInsertValues	Verify that the sql statement inserts values into a table.
toUseColumnsInCorrectOrder	Verify that the sql statement uses all specified columns in the correct order.
toUseWhereClause	Verify that the sql statement uses the specified where clause.
toOrderBy	Verify that the sql statement orders by the specified column.
toGroupBy	Verify that the sql statement groups the result by the specified column.

toInsertIntoTable

This function can be used to verify that an SQL statement inserts into a table. The following example checks if the SQL statement inserts into the table table setting the columns column1 and column2 in the correct order and uses the column1 in an ON CONFLICT clause and still setting column2.

expect(`
    INSERT INTO table (
        column1
        , column2
    )
    VALUES (value1, value2)
    ON CONFLICT (column1) DO UPDATE SET
        column2 = excluded.column2
`).toInsertIntoTable('table', {
    columns: ['column1', 'column2'],
    onConflict: {
        keys: ['column1'],
        updateSet: true,
    },
});

manyOf

This function can be used to create multiple (exactly three) test objects.

interface MyObject {
    id: string,
    value: number,
}

// Function to create an instance of MyObject with random values
function createMyObject (template?: Partial<MyObject>): MyObject {
    return {
        id: getRandomId(),
        value: getRandomValue(),
        ...template,
    };
}

// In a test:
const myObjects = manyOf(createMyObject);

// Or setting fix values
const myObject = manyOf(() => createMyObject({ value: 42 }));

// Or setting values by index
const myObject = manyOf(createMyObject, index => ({ id: `${index}` }));