Built-in Filters

Each .toml file in this directory defines one filter and its inline tests. Files are concatenated alphabetically by build.rs into a single TOML blob embedded in the binary.

Adding a filter

1. Copy any existing .toml file and rename it (e.g. my-tool.toml)
2. Update the three required fields: description, match_command, and at least one action field
3. Add [[tests.my-tool]] entries to verify the filter behaves correctly
4. Run cargo test — the build step validates TOML syntax and runs inline tests

File format

[filters.my-tool]
description = "Short description of what this filter does"
match_command = "^my-tool\\b"          # regex matched against the full command string
strip_ansi = true                       # optional: strip ANSI escape codes first
strip_lines_matching = [               # optional: drop lines matching any of these regexes
  "^\\s*$",
  "^noise pattern",
]
max_lines = 40                          # optional: keep only the first N lines after filtering
on_empty = "my-tool: ok"               # optional: message to emit when output is empty after filtering

[[tests.my-tool]]
name = "descriptive test name"
input = "raw command output here"
expected = "expected filtered output"

Available filter fields

Field	Type	Description
description	string	Human-readable description
match_command	regex	Matches the command string (e.g. "^docker\\s+inspect")
strip_ansi	bool	Strip ANSI escape codes before processing
strip_lines_matching	regex[]	Drop lines matching any regex
keep_lines_matching	regex[]	Keep only lines matching at least one regex
replace	array	Regex substitutions ({ pattern, replacement })
match_output	array	Short-circuit rules ({ pattern, message })
truncate_lines_at	int	Truncate lines longer than N characters
max_lines	int	Keep only the first N lines
tail_lines	int	Keep only the last N lines (applied after other filters)
on_empty	string	Fallback message when filtered output is empty

Naming convention

Use the command name as the filename: terraform-plan.toml, docker-inspect.toml, mix-compile.toml. For commands with subcommands, prefer <cmd>-<subcommand>.toml over grouping multiple filters in one file.