Merge pull request #222 from Ndsanes/fix/craft-fonts-relative-path

Build: resolve a relative CRAFT_FONTS_DIR against the workspace root

crates/engine/build.rs

@@ -7,16 +7,20 @@
 //! `.wasm` within the web size budget (Cloudflare serves at most 25 MiB per file); the export
 //! watermark falls back to it there. Native builds embed every font.
 use std::fmt::Write as _;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 fn main() {
     println!("cargo::rerun-if-changed=build.rs");
     println!("cargo::rerun-if-env-changed=CRAFT_FONTS_DIR");
     println!("cargo::rerun-if-env-changed=CRAFT_FONTS_REQUIRED");
     let mut src = String::from("pub static CRAFT_FONTS: &[CraftFont] = &[\n");
-    if let Some(dir) = std::env::var_os("CRAFT_FONTS_DIR").map(PathBuf::from) {
+    let mut embedded = 0;
+    if let Some(dir) = std::env::var_os("CRAFT_FONTS_DIR").map(PathBuf::from).map(resolve) {
         match craft_fonts(&dir) {
-            Ok(entries) => src.push_str(&entries),
+            Ok(entries) => {
+                embedded = entries.lines().count();
+                src.push_str(&entries);
+            }
             Err(e) if std::env::var_os("CRAFT_FONTS_REQUIRED").is_some() => {
                 println!("cargo::error=CRAFT_FONTS_DIR={}: {e}", dir.display());
             }
@@ -24,14 +28,37 @@ fn main() {
         }
     }
     src.push_str("];\n");
+    // Without them the app still runs and every language still selectable, so Chinese and Japanese
+    // just paint boxes — the one failure a user cannot diagnose from what they see.
+    if embedded == 0 {
+        println!(
+            "cargo::warning=no craft-fonts embedded: Chinese and Japanese text will render as empty boxes. \
+             Clone https://github.com/storytold/craft-fonts next to this repo and rebuild with \
+             CRAFT_FONTS_DIR=../craft-fonts"
+        );
+    }
     let out = PathBuf::from(std::env::var_os("OUT_DIR").unwrap_or_default()).join("craft_fonts.rs");
     if let Err(e) = std::fs::write(&out, src) {
         println!("cargo::error=writing {}: {e}", out.display());
     }
 }
 
+/// Resolve a relative `CRAFT_FONTS_DIR` against both roots a caller might mean: a build script's
+/// cwd is the *package* root (`crates/engine`), while the `../craft-fonts` the README and
+/// craft-fonts' docs use is written relative to the *workspace* root and would otherwise resolve
+/// to `crates/craft-fonts`.
+fn resolve(dir: PathBuf) -> PathBuf {
+    if dir.is_absolute() {
+        return dir;
+    }
+    let package = PathBuf::from(std::env::var_os("CARGO_MANIFEST_DIR").unwrap_or_default());
+    let workspace = package.parent().and_then(Path::parent).unwrap_or(package.as_path());
+    let candidates = [workspace.join(&dir), package.join(&dir)];
+    candidates.iter().find(|candidate| candidate.is_dir()).cloned().unwrap_or_else(|| candidates[0].clone())
+}
+
 /// One `CraftFont { .. }` initialiser per manifest line.
-fn craft_fonts(dir: &std::path::Path) -> Result<String, String> {
+fn craft_fonts(dir: &Path) -> Result<String, String> {
     let manifest = dir.join("fonts/manifest.txt");
     println!("cargo::rerun-if-changed={}", manifest.display());
     let text = std::fs::read_to_string(&manifest).map_err(|e| format!("{}: {e}", manifest.display()))?;