dynamic_buffer_stream unit tests

It covers:

• dynamic_buffer_stream_default_cfg()
• dynamic_buffer_stream_default_env()
• dynamic_buffer_stream_create_stream()
• dynamic_buffer_stream_create_desc()
• dynamic-buffer-backed runtime behavior through:
  • stream_write()
  • stream_read()
  • stream_flush()
  • stream_destroy() (via backend close)

---

dynamic_buffer_stream_default_cfg() unit tests

See dynamic_buffer_stream_default_cfg() specifications

Functions under test

dynamic_buffer_stream_cfg_t dynamic_buffer_stream_default_cfg(void);

Test doubles

• none

Tested scenarios

WHEN	EXPECT
dynamic_buffer_stream_default_cfg() is called	returns a dynamic_buffer_stream_cfg_t such that ret.default_cap > 0

Notes

• This helper establishes the default configuration invariant for the dynamic_buffer_stream adapter.
• The exact value of default_cap is not part of the public contract; only its validity (non-zero) is guaranteed.

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dynamic_buffer_stream_default_env() unit tests

See dynamic_buffer_stream_default_env() specifications

Functions under test

dynamic_buffer_stream_env_t dynamic_buffer_stream_default_env(
    const osal_mem_ops_t *mem,
    const stream_env_t *port_env);

Success

• ret.mem == mem
• ret.port_env == *port_env

Failure

• None

Test doubles

• dummy osal_mem_ops_t *
• dummy stream_env_t

Tested scenarios

WHEN	EXPECT
dynamic_buffer_stream_default_env(mem, port_env) is called with valid inputs	returns a dynamic_buffer_stream_env_t such that ret.mem == mem and ret.port_env == *port_env

Notes

• This helper preserves the injected memory dependency and the forwarded stream port environment provided by the caller.

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dynamic_buffer_stream_create_stream() unit tests

See dynamic_buffer_stream_create_stream() specifications

Functions under test

stream_status_t dynamic_buffer_stream_create_stream(
    stream_t **out,
    const dynamic_buffer_stream_cfg_t *cfg,
    const dynamic_buffer_stream_env_t *env);

Test doubles

• fake memory allocator (fake_memory)

Tested scenarios

WHEN	EXPECT
valid inputs	returns STREAM_STATUS_OK, stores a non-NULL stream in *out
out == NULL	returns STREAM_STATUS_INVALID
cfg == NULL	returns STREAM_STATUS_INVALID, *out unchanged
env == NULL	returns STREAM_STATUS_INVALID, *out unchanged
allocation fails	returns STREAM_STATUS_OOM, *out unchanged

Notes

• Output pointer preservation is explicitly verified using sentinel values.
• Successful creation is followed by basic borrower API checks (write, flush).

---

dynamic_buffer_stream_create_desc() unit tests

See dynamic_buffer_stream_create_desc() specifications

Functions under test

stream_status_t dynamic_buffer_stream_create_desc(
    stream_adapter_desc_t *out,
    stream_key_t key,
    const dynamic_buffer_stream_cfg_t *cfg,
    const dynamic_buffer_stream_env_t *env,
    const osal_mem_ops_t *mem);

Test doubles

• fake memory allocator (fake_memory)

Tested scenarios

WHEN	EXPECT
valid inputs	returns STREAM_STATUS_OK, produces a valid descriptor
out == NULL	returns STREAM_STATUS_INVALID
key == NULL	returns STREAM_STATUS_INVALID, resets descriptor
key == ""	returns STREAM_STATUS_INVALID, resets descriptor
cfg == NULL	returns STREAM_STATUS_INVALID, resets descriptor
env == NULL	returns STREAM_STATUS_INVALID, resets descriptor
mem == NULL	returns STREAM_STATUS_INVALID, resets descriptor
allocation fails	returns STREAM_STATUS_OOM, resets descriptor

Notes

• Descriptor validity includes:
  • non-empty key
  • non-NULL constructor
  • non-NULL user data and destructor
• Descriptor reset semantics are enforced on failure.

---

dynamic_buffer_stream_write() unit tests

See:

• dynamic_buffer_stream_write() specifications
• stream_write() specifications

Functions under test

size_t stream_write(stream_t *s, const void *buf, size_t n, stream_status_t *st);

Tested scenarios

WHEN	EXPECT
valid write without growth	writes n, appends data, read_pos unchanged
valid write with growth	writes n, buffer grows
n == 0	returns 0, no change
buf == NULL && n == 0	returns 0, no change
buf == NULL && n > 0	returns 0, STREAM_STATUS_INVALID
reserve fails	returns 0, STREAM_STATUS_OOM, no change
size overflow	returns 0, STREAM_STATUS_INVALID, no change

Notes

• Backend invariants are validated before and after the call.
• Failure paths ensure strict non-mutation of backend state.

---

dynamic_buffer_stream_read() unit tests

See:

• dynamic_buffer_stream_read() specifications
• stream_read() specifications

Functions under test

size_t stream_read(stream_t *s, void *buf, size_t n, stream_status_t *st);

Tested scenarios

WHEN	EXPECT
read within available data	returns n, advances read_pos
read beyond available data	returns remaining bytes
n == 0	returns 0, no change
buf == NULL && n == 0	returns 0, no change
buf == NULL && n > 0	returns 0, STREAM_STATUS_INVALID
EOF	returns 0, STREAM_STATUS_EOF, no change

Notes

• Read operations never modify len or buffer content.
• Only read_pos is advanced on success.

---

dynamic_buffer_stream_flush() unit tests

See dynamic_buffer_stream_flush() specifications

Functions under test

stream_status_t stream_flush(stream_t *s);

Tested scenarios

WHEN	EXPECT
flush is called	returns STREAM_STATUS_OK, backend unchanged

Notes

• This adapter implements flush as a no-op.

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dynamic_buffer_stream_close() unit tests

See:

• dynamic_buffer_stream_close() specifications
• stream_destroy() specifications

Functions under test

void stream_destroy(stream_t **s);

Tested scenarios

WHEN	EXPECT
destroy is called on a valid stream	releases backend resources, sets *s to NULL

Notes

• The private close callback is exercised indirectly via stream_destroy().
• Memory correctness is validated using fake_memory invariants.