refactor(pdf): use shared writer for export and print (PDF.W1)

xtask/src/main.rs

@@ -9,6 +9,7 @@ mod brands;
 mod bundle;
 mod ico;
 mod layers;
+mod pdf_deps;
 mod pngsuite;
 mod sha256;
 mod stats;
@@ -24,9 +25,10 @@ usage: cargo xtask <command>
 commands:
   assets          check that every icon/image/font/asset is attributed in ASSETS.md
   brands          check that user-visible text (labels, params docs, MCP, docs, packaging) names no other vendor's products
+  pdf-deps        verify immutable shared PDF writer and patched Krilla sources
   layers          enforce the crate dependency layering (plan/architecture.md §3)
   wasm            cargo check --target wasm32-unknown-unknown for the wasm-safe crates
-  ci              fmt --check, clippy -D warnings, test, assets, brands, layers, wasm (stops at first failure)
+  ci              fmt --check, clippy -D warnings, test, pdf-deps, assets, brands, layers, wasm (stops at first failure)
   corpus [--download] [--affinity]
                   show where test corpora live; --download fetches PngSuite into corpus/pngsuite,
                   --affinity the pinned public Affinity documents into corpus/affinity
@@ -45,6 +47,7 @@ fn main() -> ExitCode {
         Some("assets") => assets::run(&root()),
         Some("brands") => brands::run(&root()),
         Some("layers") => cmd_layers(),
+        Some("pdf-deps") => pdf_deps::run(&root()),
         Some("wasm") => cmd_wasm(),
         Some("ci") => cmd_ci(),
         Some("corpus") if rest.contains(&"--affinity") => affinity_corpus::fetch(),
@@ -200,6 +203,7 @@ fn cmd_ci() -> Result<(), String> {
                 run(c, "cargo test --workspace")
             }),
         ),
+        ("pdf-deps", Box::new(|| pdf_deps::run(&root()))),
         ("assets", Box::new(|| assets::run(&root()))),
         ("brands", Box::new(|| brands::run(&root()))),
         ("layers", Box::new(cmd_layers)),

xtask/src/pdf_deps.rs

@@ -0,0 +1,98 @@
+//! Verify that PDF writing uses one immutable shared crate and its patched writer backend.
+
+use std::path::Path;
+use std::process::Command;
+
+use serde_json::Value;
+
+const REV: &str = "c3487320b2d1de657b860b3c8abb44e1f2b32bd8";
+const PACKAGES: &[(&str, &str)] = &[("craft-pdf", "0.1.0"), ("krilla", "0.8.2")];
+
+pub fn run(root: &Path) -> Result<(), String> {
+    let output = Command::new(std::env::var_os("CARGO").unwrap_or_else(|| "cargo".into()))
+        .current_dir(root)
+        .args(["metadata", "--locked", "--format-version", "1"])
+        .output()
+        .map_err(|e| format!("cargo metadata: {e}"))?;
+    if !output.status.success() {
+        return Err(format!("cargo metadata: {}", String::from_utf8_lossy(&output.stderr)));
+    }
+    let metadata: Value = serde_json::from_slice(&output.stdout).map_err(|e| format!("cargo metadata: {e}"))?;
+    validate(&metadata)?;
+    println!("PDF writer: shared crate and patched backend resolve once to {REV}");
+    Ok(())
+}
+
+fn validate(metadata: &Value) -> Result<(), String> {
+    let packages = metadata.get("packages").and_then(Value::as_array).ok_or("cargo metadata has no packages")?;
+    let source = format!("git+https://github.com/storytold/craft-libs?rev={REV}#{REV}");
+    for &(name, version) in PACKAGES {
+        let mut found = packages.iter().filter(|p| p.get("name").and_then(Value::as_str) == Some(name));
+        let package = found.next().ok_or_else(|| format!("{name}: missing resolved package"))?;
+        if found.next().is_some() {
+            return Err(format!("{name}: expected one resolved package"));
+        }
+        if package.get("version").and_then(Value::as_str) != Some(version) || package.get("source").and_then(Value::as_str) != Some(source.as_str()) {
+            return Err(format!("{name}: expected {version} from {source}; got {package}"));
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    fn metadata() -> Value {
+        let packages: Vec<_> = PACKAGES
+            .iter()
+            .map(|(name, version)| {
+                json!({
+                    "name":name, "version":version,
+                    "source":format!("git+https://github.com/storytold/craft-libs?rev={REV}#{REV}")
+                })
+            })
+            .collect();
+        json!({"packages": packages})
+    }
+
+    #[test]
+    fn accepts_the_pinned_writer_without_changing_reader_sources() {
+        let mut m = metadata();
+        m["packages"]
+            .as_array_mut()
+            .unwrap()
+            .push(json!({"name":"hayro-syntax", "version":"0.7.2", "source":"registry+https://github.com/rust-lang/crates.io-index"}));
+        assert!(validate(&m).is_ok());
+    }
+
+    #[test]
+    fn rejects_missing_or_duplicate_writer_packages() {
+        for index in 0..PACKAGES.len() {
+            let mut m = metadata();
+            m["packages"].as_array_mut().unwrap().remove(index);
+            assert!(validate(&m).is_err());
+            let mut m = metadata();
+            let duplicate = m["packages"][index].clone();
+            m["packages"].as_array_mut().unwrap().push(duplicate);
+            assert!(validate(&m).is_err());
+        }
+    }
+
+    #[test]
+    fn rejects_registry_local_version_and_revision_drift() {
+        for index in 0..PACKAGES.len() {
+            for (field, value) in [
+                ("source", Value::Null),
+                ("source", json!("registry+https://github.com/rust-lang/crates.io-index")),
+                ("source", json!("git+https://github.com/storytold/craft-libs?branch=main#other")),
+                ("version", json!("0.99.0")),
+            ] {
+                let mut m = metadata();
+                m["packages"][index][field] = value;
+                assert!(validate(&m).is_err());
+            }
+        }
+    }
+}