CLIM-1339: Download processing finch error

[renoirb]

Description

On the Download page, requesting data for certain Health Region selections (InteractiveRegionOption.HEALTH) failed in Finch: the job errored, no file was produced, and the user received an error email instead of their data.

Root cause. The selected region's display name is sent to Finch as the output_name input — the label Finch uses to name the output file. Two of the 119 health-region names contain a forward slash:

• North Shore/Coast Garibaldi Health Service Delivery Area
• Thompson/Cariboo Health Service Delivery Area

Finch builds its output path from output_name and reads the / as a directory separator, so it attempts to write into a sub-directory that does not exist:

Finch failed with Cannot save file into a non-existent directory: tx_tn_days_above_health_North Shore
Finch failed with Errno 13 Permission denied: /code/tx_tn_days_above_health_North Shore/coast_garibaldi…

Two message variants across the failing jobs, one cause — the / split.

Fix. Before output_name is pushed to the Finch inputs, replace the path separators / and \ with _:

outputName = outputName.replace(/[/\\]/g, '_');

North Shore/Coast Garibaldi… is then sent as …North Shore_Coast Garibaldi…, which Finch accepts and stores as …north_shore_coast_garibaldi… — matching a known-good run.

Why only the slash. Finch already normalizes the rest of the name itself — it lower-cases, replaces spaces and punctuation with _, ASCII-folds accents, and transliterates non-ASCII letters. Verified against real jobs:

• Région de l'Estrie was submitted unescaped (accent + apostrophe + spaces) and succeeded, returning …region_de_l_estrie….zip. So accents, apostrophes and dashes are not the cause.

• Tłı̨chǫ Community Services Agen (letters that do not NFKD-fold: ł ı ǫ) was also submitted unescaped and succeeded, returning …tlicho_community_services_agen… — Finch transliterates ł→l, ı→i, ǫ→o (see on the map click near 'Northwest Territories').

• The slash is special only because Finch consumes it as a path separator before that normalization runs.

A scan of all 119 names in the GeoServer CDC:health layer found exactly 2 with / (the two above); the rest carry accents, dashes, apostrophes and even non-Latin letters — all of which Finch handles on its own. The slash fix therefore covers the failure for the entire layer.

Scope & safety.

• Download app only; the change touches only the assembled output_name string.
• output_name is write-only on the frontend (nothing reads it back), so this cannot affect request matching or any other input.
• Behaviour changes only for the 2 slash-bearing regions; every other region produces the same output_name as before.

Note

Unrelated data note: Tłı̨chǫ Community Services Agen… (region id 116) is truncated in the CDC:health source layer (it should read "Agency"). It downloads correctly — Finch transliterates the name to tlicho_community_services_agen — so this is a separate layer data-quality issue.

Related ticket

• CLIM-1339