ci: add linting for maximum filename length

Related to #1659

Author: echasnovski

.github/workflows/lint.yml

@@ -56,6 +56,17 @@ jobs:
       - name: Lint new commits
         run: make --silent lintcommit-ci
 
+  lint-filename-length:
+    name: Lint filename lengths
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          ref: ${{ github.event.pull_request.head.sha || github.ref }}
+      - name: Lint filename legnths
+        run: make --silent lint-filename-length-ci
+
   case-sensitivity:
     name: File case sensitivity
     runs-on: ubuntu-latest

Makefile

@@ -30,6 +30,9 @@ documentation:
 lintcommit-ci:
 	export LINTCOMMIT_STRICT=true && chmod u+x scripts/lintcommit-ci.sh && scripts/lintcommit-ci.sh
 
+lint-filename-length-ci:
+	chmod u+x scripts/lint-filename-length.sh && scripts/lint-filename-length.sh
+
 dual_sync:
 	chmod u+x scripts/dual_sync.sh && scripts/dual_sync.sh
 

TESTING.md

@@ -987,3 +987,7 @@ return Helpers
 -- Some code setting up `child`
 local set_lines = function(lines) child.api.nvim_buf_set_lines(0, 0, -1, true, lines) end
 ```
+
+- When working with automatically named screenshots, beware of the following caveats:
+    - Some systems are case insensitive (like usually Windows and MacOS). So having two different file names which are the same ignoring case will introduce problems for users to properly install plugin.
+    - Some system setups have restrictions on full path length (like 260 bytes on some Git+Windows combinations) or file name length (like 255 bytes on ext4 Windows partitions and 143 bytes on eCryptfs Linux partitions). Restriction on full path is hard to accommodate for (apart from limiting file name size to some reasonable number), but trying to not have file names longer than 143 bytes (by having shorter test case names) should be reasonable.

scripts/lint-filename-length.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+# Exact value of maximum length is chosen as a "reasonably high but not bigger
+# than 143 (maximum filename length on eCryptfs systmes) number".
+# Having low-ish value also helps with restirctions on full path length.
+max_filename_length=125
+
+exit_code=0
+for filename in $(find . -not -path './.git/**' -not -path './dual/**' -printf %f\\n); do
+  if [ "${#filename}" -gt $max_filename_length ]; then
+    echo "Too long file name: $filename"
+    exit_code=1
+  fi
+done
+
+exit $exit_code