From cb0acc2462cade3fb763b2f732982ce533c965e1 Mon Sep 17 00:00:00 2001
From: Bernhard Schuster <bernhard@ahoi.io>
Date: Tue, 9 Apr 2024 09:01:46 +0200
Subject: [PATCH] feat: introduce `expander` for easier debugging

---
 Cargo.lock                  | 45 +++++++++++++++++++++++++++++++++++++
 progenitor-macro/Cargo.toml |  1 +
 progenitor-macro/src/lib.rs | 13 +++++++++++
 progenitor/Cargo.toml       |  1 +
 4 files changed, 60 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index f50d00a3..9d463a1b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -208,6 +208,15 @@ version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4682ae6287fcf752ecaabbfcc7b6f9b72aa33933dc23a554d853aea8eea8635"
 
+[[package]]
+name = "blake2"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46502ad458c9a52b69d4d4d32775c788b7a1b85e8bc9d482d92250fc0e3f8efe"
+dependencies = [
+ "digest",
+]
+
 [[package]]
 name = "block-buffer"
 version = "0.10.2"
@@ -456,6 +465,7 @@ checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
  "block-buffer",
  "crypto-common",
+ "subtle",
 ]
 
 [[package]]
@@ -643,6 +653,20 @@ dependencies = [
  "wasm-bindgen-test",
 ]
 
+[[package]]
+name = "expander"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00e83c02035136f1592a47964ea60c05a50e4ed8b5892cfac197063850898d4d"
+dependencies = [
+ "blake2",
+ "fs-err",
+ "prettier-please",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.66",
+]
+
 [[package]]
 name = "expectorate"
 version = "1.1.0"
@@ -690,6 +714,15 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "fs-err"
+version = "2.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88a41f105fe1d5b6b34b2055e3dc59bb79b46b48b2040b9e6c7b4b5de097aa41"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.30"
@@ -1374,6 +1407,16 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
+[[package]]
+name = "prettier-please"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22020dfcf177fcc7bf5deaf7440af371400c67c0de14c399938d8ed4fb4645d3"
+dependencies = [
+ "proc-macro2",
+ "syn 2.0.66",
+]
+
 [[package]]
 name = "prettyplease"
 version = "0.2.19"
@@ -1399,6 +1442,7 @@ version = "0.7.0"
 dependencies = [
  "base64 0.22.1",
  "chrono",
+ "expander",
  "futures",
  "percent-encoding",
  "progenitor-client",
@@ -1461,6 +1505,7 @@ dependencies = [
 name = "progenitor-macro"
 version = "0.7.0"
 dependencies = [
+ "expander",
  "openapiv3",
  "proc-macro2",
  "progenitor-impl",
diff --git a/progenitor-macro/Cargo.toml b/progenitor-macro/Cargo.toml
index c7af7197..469ae0f9 100644
--- a/progenitor-macro/Cargo.toml
+++ b/progenitor-macro/Cargo.toml
@@ -21,3 +21,4 @@ serde_json = "1.0"
 serde_yaml = "0.9"
 serde_tokenstream = "0.2.0"
 syn = { version = "2.0", features = ["full", "extra-traits"] }
+expander = "2"
diff --git a/progenitor-macro/src/lib.rs b/progenitor-macro/src/lib.rs
index 60111f3b..f25156f7 100644
--- a/progenitor-macro/src/lib.rs
+++ b/progenitor-macro/src/lib.rs
@@ -405,5 +405,18 @@ fn do_generate_api(item: TokenStream) -> Result<TokenStream, syn::Error> {
         const _: &str = include_str!(#path_str);
     };
 
+    let output = if let Some(dest) = std::env::var("PROGENITOR_OUTPUT_DEBUG")
+        .map(std::path::PathBuf::from_str)
+    {
+        eprintln!("Writing generated output to {}", path.display());
+        expander::Expander::new(dest.filename().expect("Environment var `PROGENITOR_OUTPUT_DEBUG` must contain path with filename"))
+        .fmt(expander::Edition::_2021)
+        .verbose(true)
+        .write_to(output, dest.parent().expect("If path has filename, parent must be root / drive at least. qed"))
+        .write_to_out_dir(output)
+        .expect("Writing file works. qed")
+    } else {
+        output
+    };
     Ok(output.into())
 }
diff --git a/progenitor/Cargo.toml b/progenitor/Cargo.toml
index 014806a8..2e030397 100644
--- a/progenitor/Cargo.toml
+++ b/progenitor/Cargo.toml
@@ -14,6 +14,7 @@ progenitor-client = { version = "0.7.0", path = "../progenitor-client" }
 progenitor-impl = { version = "0.7.0", path = "../progenitor-impl" }
 progenitor-macro = { version = "0.7.0", path = "../progenitor-macro" }
 serde_json = "1.0"
+expander = "2.1.0"
 
 [dev-dependencies]
 base64 = "0.22"