phasm/tests/integration/test_lang/generator.md

# runtime_extract_value_literal

As a developer
I want to extract a $TYPE value
In order get the result I calculated with my phasm code

```py
@exported
def testEntry() -> $TYPE:
    return $VAL0
```

```py
expect(VAL0)
```

# runtime_extract_value_round_trip

As a developer
I want to extract a $TYPE value that I've input
In order let the code select a value that I've predefined

```py
@exported
def testEntry(x: $TYPE) -> $TYPE:
    return x
```

```py
expect(VAL0, given=[VAL0])
```

# module_constant_def_ok

As a developer
I want to define $TYPE module constants
In order to make hardcoded values more visible
and to make it easier to change hardcoded values

```py
CONSTANT: $TYPE = $VAL0

@exported
def testEntry() -> i32:
    return 9
```

```py
expect(9)
```

# module_constant_def_bad

As a developer
I want to receive a type error on an invalid assignment on a $TYPE module constant
In order to make debugging easier

```py
CONSTANT: (u32, ) = $VAL0
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
    expect_type_error(
        'Tuple element count mismatch',
        'The given literal must fit the expected type',
    )
else:
    expect_type_error(
        'Must be tuple',
        'The given literal must fit the expected type',
    )
```

# function_result_is_literal_ok

As a developer
I want to use return a literal from a function
In order to define constants in a more dynamic way

```py
def drop_arg_return_9(x: $TYPE) -> i32:
    return 9

def constant() -> $TYPE:
    return $VAL0

@exported
def testEntry() -> i32:
    return drop_arg_return_9(constant())
```

```py
expect(9)
```

# function_result_is_literal_bad

As a developer
I want to receive a type error when returning a $TYPE literal for a function that doesn't return that type
In order to make debugging easier

```py
def drop_arg_return_9(x: (u32, )) -> i32:
    return 9

def constant() -> (u32, ):
    return $VAL0

@exported
def testEntry() -> i32:
    return drop_arg_return_9(constant())
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
    expect_type_error(
        'Mismatch between applied types argument count',
        'The type of a tuple is a combination of its members',
    )
elif TYPE_NAME.startswith('struct_'):
    expect_type_error(
        TYPE + ' must be (u32, ) instead',
        'The type of the value returned from function constant should match its return type',
    )
else:
    expect_type_error(
        'Must be tuple',
        'The given literal must fit the expected type',
    )
```

# function_result_is_module_constant_ok

As a developer
I want to use return a $TYPE module constant from a function
In order to use my module constants in return statements

```py
CONSTANT: $TYPE = $VAL0

def helper(x: $TYPE) -> i32:
    return 9

def constant() -> $TYPE:
    return CONSTANT

@exported
def testEntry() -> i32:
    return helper(constant())
```

```py
expect(9)
```

# function_result_is_module_constant_bad

As a developer
I want to receive a type error when returning a $TYPE module constant for a function that doesn't return that type
In order to make debugging easier

```py
CONSTANT: $TYPE = $VAL0

def drop_arg_return_9(x: (u32, )) -> i32:
    return 9

def constant() -> (u32, ):
    return CONSTANT

@exported
def testEntry() -> i32:
    return drop_arg_return_9(constant())
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
    expect_type_error(
        TYPE + ' must be (u32, ) instead',
        'The type of the value returned from function constant should match its return type',
    )
else:
    expect_type_error(
        TYPE_NAME + ' must be (u32, ) instead',
        'The type of the value returned from function constant should match its return type',
    )
```

# function_result_is_arg_ok

As a developer
I want to use return a $TYPE function argument
In order to make it possible to select a value using a function

```py
CONSTANT: $TYPE = $VAL0

def drop_arg_return_9(x: $TYPE) -> i32:
    return 9

def select(x: $TYPE) -> $TYPE:
    return x

@exported
def testEntry() -> i32:
    return drop_arg_return_9(select(CONSTANT))
```

```py
expect(9)
```

# function_result_is_arg_bad

As a developer
I want to receive a type error when returning a $TYPE argument for a function that doesn't return that type
In order to make debugging easier

```py
def drop_arg_return_9(x: (u32, )) -> i32:
    return 9

def select(x: $TYPE) -> (u32, ):
    return x
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
    expect_type_error(
        TYPE + ' must be (u32, ) instead',
        'The type of the value returned from function select should match its return type',
    )
else:
    expect_type_error(
        TYPE_NAME + ' must be (u32, ) instead',
        'The type of the value returned from function select should match its return type',
    )
```

# function_arg_literal_ok

As a developer
I want to use a $TYPE literal by passing it to a function
In order to use a pre-existing function with the values I specify

```py
def helper(x: $TYPE) -> i32:
    return 9

@exported
def testEntry() -> i32:
    return helper($VAL0)
```

```py
expect(9)
```

# function_arg_literal_bad

As a developer
I want to receive a type error when passing a $TYPE literal to a function that does not accept it
In order to make debugging easier

```py
def helper(x: (u32, )) -> i32:
    return 9

@exported
def testEntry() -> i32:
    return helper($VAL0)
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_'):
    expect_type_error(
        'Mismatch between applied types argument count',
        # FIXME: Shouldn't this be the same as for the else statement?
        'The type of a tuple is a combination of its members',
    )
elif TYPE_NAME.startswith('struct_'):
    expect_type_error(
        TYPE + ' must be (u32, ) instead',
        'The type of the value passed to argument x of function helper should match the type of that argument',
    )
else:
    expect_type_error(
        'Must be tuple',
        'The given literal must fit the expected type',
    )
```

# function_arg_module_constant_def_ok

As a developer
I want to use a $TYPE module constant by passing it to a function
In order to use my defined value with a pre-existing function

```py
CONSTANT: $TYPE = $VAL0

def helper(x: $TYPE) -> i32:
    return 9

@exported
def testEntry() -> i32:
    return helper(CONSTANT)
```

```py
expect(9)
```

# function_arg_module_constant_def_bad

As a developer
I want to receive a type error when passing a $TYPE module constant to a function that does not accept it
In order to make debugging easier

```py
CONSTANT: $TYPE = $VAL0

def helper(x: (u32, )) -> i32:
    return 9

@exported
def testEntry() -> i32:
    return helper(CONSTANT)
```

```py
if TYPE_NAME.startswith('tuple_') or TYPE_NAME.startswith('static_array_') or TYPE_NAME.startswith('struct_'):
    expect_type_error(
        TYPE + ' must be (u32, ) instead',
        'The type of the value passed to argument x of function helper should match the type of that argument',
    )
else:
    expect_type_error(
        TYPE_NAME + ' must be (u32, ) instead',
        'The type of the value passed to argument x of function helper should match the type of that argument',
    )
```