Nullable SHOULD be set to false for collection values (e.g. sets, maps, lists) when using them in loops. However for scalar values like string and number, a null value MAY have a semantic meaning and as such these values are allowed.

Precise local types SHOULD be used.

Good example:

{
  name = "John"
  age  = 52
}

Bad example:

{
  name = "John"
  age  = "52" # age should be number
}

From Terraform AzureRM 3.0, the default value of prevent_deletion_if_contains_resources in provider block is true. This will lead to an unstable test because the test subscription has some policies applied, and they will add some extra resources during the run, which can cause failures during destroy of resource groups.

For the definition of resources in the same file, the resources be depended on SHOULD come first, after them are the resources depending on others.

There are 3 types of assignment statements in a resource or data block: argument, meta-argument and nested block. The argument assignment statement is a parameter followed by =:

The meta-arguments below SHOULD be declared on the top of a module block with the following order:

1. source
2. version
3. count
4. for_each

blank lines will be used to separate them.