refactor: use build.rs for testing subplotlib subplots

A bit of dog-fooding: use subplot-build to test subplotlib.

Add a subplotlib/build.rs script to generate test code in Rust for the
subplotlib/*.md subplots. The generated code is included in
tests/*.rs, and run with "cargo test". Drop the same functionality
from the ./check script..

Sponsored-by: author

1 files changed, 30 insertions, 0 deletions

diff --git a/subplotlib/build.rs b/subplotlib/build.rs
new file mode 100644
index 0000000..5f94883
--- /dev/null
+++ b/subplotlib/build.rs
@@ -0,0 +1,30 @@
+// Build script for subplotlib.
+//
+// We use the `subplot_build` crate to generate a Rust test code file
+// with functions for the scenarios for each subplot file
+// (subplot/*.md in the source tree). The generated file is written to
+// the Cargo target directory. For each subplot foo.md there should be
+// a tests/foo.rs in the source tree, which includes the generated
+// file from the Cargo target tree. The source file should look like this:
+//
+// ```rust
+// include!(concat!(env!("OUT_DIR"), "/foo.rs"));
+// ```
+
+use glob::glob;
+use std::path::Path;
+
+fn main() {
+    let subplots = glob("*.md").expect("failed to find subplots in subplotlib");
+    let tests = Path::new("tests");
+    for entry in subplots {
+        let entry = entry.expect("failed to get subplot dir entry in subplotlib");
+        let mut inc = tests.join(&entry);
+        inc.set_extension("rs");
+        if !inc.exists() {
+            panic!("missing include file: {}", inc.display());
+        }
+        println!("cargo:rerun-if-changed={}", inc.display());
+        subplot_build::codegen(Path::new(&entry)).expect("failed to generate code with Subplot");
+    }
+}