Merge pull request #24 from asglover/main

Author: saulshanabrook

Cargo.toml

@@ -13,6 +13,7 @@ readme = "README.md"
 default = ["serde"]
 serde = ["dep:serde", "dep:serde_json", "indexmap/serde", "ordered-float/serde"]
 graphviz = ["dep:graphviz-rust"]
+graphviz-exec = ["graphviz", "graphviz-rust/graphviz-exec"]
 
 [dependencies]
 indexmap = "2"
@@ -31,6 +32,7 @@ optional = true
 version = "1.0.100"
 
 [dependencies.graphviz-rust]
+default-features = false
 optional = true
 version = "0.9"
 

README.md

@@ -42,5 +42,10 @@ Don't forget to add something to `root_eclasses` on the resulting serialized egr
 
 Check out the [`./tests-viz`](./tests-viz/README.md) directory to view visualizations of all the test cases with Graphviz.
 
+To remake them, run `make tests` from the root of this repo. 
 
-To remake them, run `make tests` from the root of this repo. Any tests that don't have SVG visualizations created yet will be generated. You'll need to have [Graphviz](https://graphviz.org/) installed.
+### SVG Generation 
+Generating SVG files requires having [Graphviz](https://graphviz.org/) installed. This cannot be distributed through rust's crates toolchain, so the function `to_svg_file` is gated behind the `graphviz-exec` feature flag. 
+
+### DOT Generation
+The `graphviz-rust` crate can produce `.dot` files without requiring the existence of the [Graphviz](https://graphviz.org/) CLI tool. Therefore creation of dot files and other functionality which only relies on `graphviz-rust` is gated behind the `graphviz` feature flag. 

src/graphviz.rs

@@ -16,6 +16,7 @@ impl EGraph {
         self.to_graphviz().print(&mut PrinterContext::default())
     }
 
+    #[cfg(feature = "graphviz-exec")]
     pub fn to_svg_file(&self, path: impl AsRef<std::path::Path>) -> std::io::Result<()> {
         graphviz_rust::exec_dot(
             self.to_dot(),

tests/round_trip.rs

@@ -2,6 +2,7 @@ use std::path::{Path, PathBuf};
 
 use egraph_serialize::*;
 
+#[cfg(feature = "serde")]
 #[test]
 fn test_round_trip() {
     let mut n_tested = 0;
@@ -14,25 +15,20 @@ fn test_round_trip() {
     assert!(n_tested > 0);
 }
 
-#[cfg(feature = "graphviz")]
+#[cfg(all(feature = "serde", feature = "graphviz"))]
 #[test]
 fn test_graphviz() {
-    // Check if `dot` command is available
-    let no_dot = std::process::Command::new("dot")
-        .arg("-V")
-        .status()
-        .is_err();
-
     let mut names = Vec::new();
     for entry in test_files() {
         println!("Testing graphviz {entry:?}");
         let mut egraph = EGraph::from_json_file(entry.as_path()).unwrap();
         names.push(entry.file_stem().unwrap().to_str().unwrap().to_string());
 
-        // If graphviz isn't installed, just test that we can create the dot string, not generate the SVG
-        if no_dot {
-            egraph.to_dot();
-        } else {
+        egraph.to_dot(); // Always test `to_dot`
+
+        // Test `to_svg` only when the graphviz-exec feature is available
+        #[cfg(feature = "graphviz-exec")]
+        {
             let path = Path::new("./tests-viz")
                 .join(entry.file_name().unwrap())
                 .with_extension("svg");
@@ -46,9 +42,10 @@ fn test_graphviz() {
         // Generate graphs with inlined leaves as well
         egraph.inline_leaves();
 
-        if no_dot {
-            egraph.to_dot();
-        } else {
+        egraph.to_dot();
+
+        #[cfg(feature = "graphviz-exec")]
+        {
             let path = Path::new("./tests-viz").join(format!(
                 "{}-inlined.svg",
                 entry.file_stem().unwrap().to_str().unwrap()
@@ -63,9 +60,11 @@ fn test_graphviz() {
 
         // Saturate inlining
         egraph.saturate_inline_leaves();
-        if no_dot {
-            egraph.to_dot();
-        } else {
+
+        egraph.to_dot();
+
+        #[cfg(feature = "graphviz-exec")]
+        {
             let path = Path::new("./tests-viz").join(format!(
                 "{}-inlined-saturated.svg",
                 entry.file_stem().unwrap().to_str().unwrap()