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7. Health checks

what `fontina check` looks for, every check identifier, and the exit status rules.

fontina check is a small, fast subset of what fontbakery does: the checks that catch a broken or misdeclared font before it reaches a project, not the checks that judge its design. It runs on indexed faces or on any file.

$ fontina check ~/Fonts/*.ttf
PASS  Amiri Regular  (/home/me/Fonts/Amiri-Regular.ttf#0)  0 error(s), 0 warning(s)
1 face(s) checked, 0 failed

Levels and exit status

Each finding has a level:

error: the font is malformed or unusable as declared. check exits 1.
warn: the font will misbehave somewhere: wrong style linking, unshaped text, varying line height. check exits 0 unless --strict.
info: worth knowing, not wrong.

--min warn hides info findings; --min error hides warnings too. --json prints every finding with its id, level and message.

Identifiers

Every check has an identifier area/check. Identifiers are stable: one is never renamed or reused, so a script that ignores hinting/none today will still ignore it in ten years. New checks are added under a new identifier and announced in the changelog. Some identifiers are reported at more than one level depending on what was found.

Id	Level	Finding
`name/family`	error	no family name (name IDs 1 and 16 are empty)
`name/postscript`	error, warn	no PostScript name; or one that is over 63 characters or contains characters outside printable ASCII
`name/full-name`	warn	full name does not start with the family name
`name/version`	warn	no version string (name ID 5), or one that is not parseable
`name/designer`	info	no designer or manufacturer recorded (name IDs 8, 9)
`name/empty`	warn	a `name` record is present but carries no text
`name/whitespace`	warn	a `name` record has leading or trailing whitespace
`os2/missing`	error	no `OS/2` table
`os2/weight-class`	error	`usWeightClass` outside 1..1000
`os2/width-class`	error	`usWidthClass` outside 1..9
`os2/bold-weight`	warn	`fsSelection` BOLD is set but `usWeightClass` disagrees
`os2/fs-selection`	warn	`fsSelection` sets REGULAR together with BOLD or ITALIC
`os2/italic-angle`	warn	`fsSelection` says italic but `post.italicAngle` is 0
`os2/fs-type`	info	`fsType` restricts embedding: no embedding, preview and print only, or bitmap only
`os2/vendor-id`	info	`achVendID` is unset or `UKWN`
`metrics/typo-vs-hhea`	warn	`OS/2` typo metrics differ from `hhea` and USE_TYPO_METRICS is not set; line height will vary by platform
`metrics/fixed-pitch`	warn	`post.isFixedPitch` and the advance widths disagree, in either direction
`metrics/line-gap`	info	`hhea.lineGap` is not zero, so line height varies by platform
`metrics/x-height`	warn	`sxHeight` is above `sCapHeight`
`head/units-per-em`	error	`unitsPerEm` outside 16..16384
`head/created`	info	`head.created` is unset
`hhea/ascender`	error	`hhea.ascender` is not positive
`hhea/descender`	warn	`hhea.descender` is positive
`glyf/empty`	error	font has no glyphs
`outlines/none`	error	no `glyf`, `CFF` or `CFF2` outlines and no bitmap strikes
`hinting/none`	info	TrueType outlines without hinting programs
`cmap/empty`	error	`cmap` maps no codepoints
`cmap/space`	warn	U+0020 SPACE is not mapped
`cmap/nbsp`	info	U+00A0 NO-BREAK SPACE is not mapped
`cmap/private-use`	info	more than a handful of codepoints in a Private Use Area, which mean nothing without this font
`cmap/basic-latin`	warn	a Latin font does not map all of A to Z
`fvar/stat`	warn	variable font without a `STAT` table; style linking will be wrong in many apps
`fvar/instances`	warn	variable font without named instances
`fvar/instance-range`	error	a named instance sits outside its own axis range
`fvar/wght-os2`	warn	the `wght` axis default disagrees with `usWeightClass`
`fvar/instance-name`	warn	named instance without a resolvable name
`fvar/axis-range`	warn	an axis has a zero-width range
`fvar/axis-tag`	warn	a lowercase axis tag that is not a registered axis; custom tags should be uppercase
`layout/shaping`	warn	the `cmap` covers a script that needs shaping, but `GSUB`/`GPOS` have no such script; text will not shape
`layout/kerning`	info	no `GPOS` table and no legacy `kern` table
`license/missing`	warn	no license text or URL embedded (name IDs 13, 14)
`license/unknown`	warn	license text present but not recognised as any SPDX license
`license/url`	info	OFL font without a license URL (name ID 14)
`license/rfn`	info	a Reserved Font Name is declared that does not match the family name
`license/free`	info	the licence grants the four freedoms
`license/nonfree`	warn	the licence withholds the freedom to change or redistribute the font
`license/embedding`	info	`OS/2.fsType` restricts embedding; fontina reports it and does not act on it
`license/copyright`	warn	no copyright notice (name ID 0)
`file/extension`	warn	the file extension does not match the container and outline format

What it does not do

It does not rasterise, so it cannot find overlapping contours, wrong-direction paths or missing glyph outlines. It does not judge vertical metrics against a family, spacing, or kerning quality. For those, run fontbakery. fontina’s checks are meant to be cheap enough to run on every scan.

Adding a check

A new check needs a new identifier under an existing or new area, a message that says what was found and where in the font, and a fixture font under an open license that triggers it with a test asserting so. See Contributing.

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