Lambda: detect transitive dependencies from higher-order functions

[sam-goodwin]

We currently do not support detecting dependencies to infer IAM Policies and automate environment variable/client instantiation if the dependency is contained within another function called by the closure.

• detect dependencies used by another function (declared outside of its scope)

const table = new Table(..);

function foo() {
  return $AWS.DynamoDB.GetItem({
    Table: table,
    ...
  });
}

new Function(scope, id, () => {
  return foo();
});

• detect dependencies passed to a function as input

function foo(table: Table) {
  return $AWS.DynamoDB.GetItem({
    Table: table,
    ...
  });
}

const table = new Table(..);

new Function(scope, id, () => {
  // dependency passed to foo
  return foo(table);
});

• detect dependencies returned from another funciton

const table = new Table(..);

function getTable() {
  return table;
}

new Function(scope, id, () => {
  return $AWS.DynamoDB.GetItem({
    // dependency returned by a function call
    Table: getTable(),
    ...
  });
});

[thantos]

The "Integration" term is inclusive of all cases here right?

[sam-goodwin]

The "Integration" term is inclusive of all cases here right?

Not sure what you mean

[thantos]

I mean the goal is a bit simpler, "find all integrations and apply them based on their contract" (bind, pre-warm, maybe call)

[thantos]

Same as #350 ?

[sam-goodwin]

declare const table1;
declare const table2;
declare const table3;

function getTables(table1) {
  return [table1, table2, table3]
}

const tables = getTables(table1);

for (const table of tables) {
  $AWS.DynamoDB.GetItem({
    Table: table,
  })
}