name = "pipeline_transform"
category = "pipeline"
mode = "solve"
description = """
Read lines from stdin. Build a pipeline that:
1. Filters to only lines containing the word "error" (case-insensitive)
2. Extracts the portion after the first colon (trimming leading whitespace)
3. Sorts the results alphabetically
4. Removes duplicate lines

Print the final result to stdout, one line per line.
"""

[[test_cases]]
stdin = """INFO: server started
ERROR: disk full
WARN: low memory
error: connection refused
ERROR: disk full
INFO: request handled
Error: timeout reached"""
expected_stdout = """connection refused
disk full
timeout reached"""

[[test_cases]]
stdin = """ERROR: alpha
ERROR: charlie
ERROR: bravo
ERROR: alpha"""
expected_stdout = """alpha
bravo
charlie"""

[[test_cases]]
stdin = """INFO: all good
WARN: nothing here"""
expected_stdout = ""