Feature-gate test-programs

This commit feature-gates `test-programs` as a workaround for
`cargo test` not allowing for optional dev-dependencies.

This commit addresses #595.

crates/test-programs/build.rs

@@ -3,17 +3,20 @@
 //! By generating a separate `#[test]` test for each file, we allow cargo test
 //! to automatically run the files in parallel.
 
-use std::env;
-use std::fs::{read_dir, DirEntry, File};
-use std::io::{self, Write};
-use std::path::{Path, PathBuf};
-use std::process::{Command, Stdio};
-
 fn main() {
-    build_and_generate_tests()
+    #[cfg(features = "test-programs")]
+    wasi_tests::build_and_generate_tests()
 }
 
-fn build_and_generate_tests() {
+#[cfg(features = "test-programs")]
+mod wasi_tests {
+    use std::env;
+    use std::fs::{read_dir, DirEntry, File};
+    use std::io::{self, Write};
+    use std::path::{Path, PathBuf};
+    use std::process::{Command, Stdio};
+
+    fn build_and_generate_tests() {
         // Validate if any of test sources are present and if they changed
         // This should always work since there is no submodule to init anymore
         let bin_tests = std::fs::read_dir("wasi-tests/src/bin").unwrap();
@@ -28,15 +31,16 @@ fn build_and_generate_tests() {
             }
         }
         // Build tests to OUT_DIR (target/*/build/wasi-common-*/out/wasm32-wasi/release/*.wasm)
-    let out_dir =
+        let out_dir = PathBuf::from(
-        PathBuf::from(env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"));
+            env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set"),
+        );
         let mut out =
             File::create(out_dir.join("wasi_tests.rs")).expect("error generating test source file");
         build_tests("wasi-tests", &out_dir).expect("building tests");
         test_directory(&mut out, "wasi-tests", &out_dir).expect("generating tests");
-}
+    }
 
-fn build_tests(testsuite: &str, out_dir: &Path) -> io::Result<()> {
+    fn build_tests(testsuite: &str, out_dir: &Path) -> io::Result<()> {
         let mut cmd = Command::new("cargo");
         cmd.args(&[
             "build",
@@ -59,9 +63,9 @@ fn build_tests(testsuite: &str, out_dir: &Path) -> io::Result<()> {
         }
 
         Ok(())
-}
+    }
 
-fn test_directory(out: &mut File, testsuite: &str, out_dir: &Path) -> io::Result<()> {
+    fn test_directory(out: &mut File, testsuite: &str, out_dir: &Path) -> io::Result<()> {
         let mut dir_entries: Vec<_> = read_dir(out_dir.join("wasm32-wasi/release"))
             .expect("reading testsuite directory")
             .map(|r| r.expect("reading testsuite directory entry"))
@@ -102,9 +106,13 @@ fn test_directory(out: &mut File, testsuite: &str, out_dir: &Path) -> io::Result
         }
         writeln!(out, "}}")?;
         Ok(())
-}
+    }
 
-fn write_testsuite_tests(out: &mut File, dir_entry: DirEntry, testsuite: &str) -> io::Result<()> {
+    fn write_testsuite_tests(
+        out: &mut File,
+        dir_entry: DirEntry,
+        testsuite: &str,
+    ) -> io::Result<()> {
         let path = dir_entry.path();
         let stemstr = path
             .file_stem()
@@ -149,9 +157,9 @@ fn write_testsuite_tests(out: &mut File, dir_entry: DirEntry, testsuite: &str) -
         writeln!(out, "    }}")?;
         writeln!(out)?;
         Ok(())
-}
+    }
 
-cfg_if::cfg_if! {
+    cfg_if::cfg_if! {
         if #[cfg(not(windows))] {
             /// Ignore tests that aren't supported yet.
             fn ignore(_testsuite: &str, _name: &str) -> bool {
@@ -176,10 +184,10 @@ cfg_if::cfg_if! {
                 }
             }
         }
-}
+    }
 
-/// Mark tests which do not require preopens
+    /// Mark tests which do not require preopens
-fn no_preopens(testsuite: &str, name: &str) -> bool {
+    fn no_preopens(testsuite: &str, name: &str) -> bool {
         if testsuite == "wasi-tests" {
             match name {
                 "big_random_buf" => true,
@@ -190,4 +198,5 @@ fn no_preopens(testsuite: &str, name: &str) -> bool {
         } else {
             unreachable!()
         }
+    }
 }

crates/test-programs/tests/wasm_tests/main.rs

@@ -1,3 +1,4 @@
+#![cfg(features = "test-programs")]
 mod runtime;
 mod utils;