Do not unnecessarily extract ocaml.tar.gz when running CI tests

Author: cknitt

scripts/buildocaml.js

@@ -7,6 +7,25 @@ var fs = require("fs");
 var ocamlSrcDir = path.join(__dirname, "..", "native");
 var ocamlVersionFilePath = path.join(ocamlSrcDir, "VERSION");
 
+/**
+ * Checks whether an OCaml compiler is available.
+ * If it is, we do not need to build one from the vendored sources.
+ */
+function checkEnvCompiler() {
+  try {
+    var o = cp.execSync(`ocamlopt.opt -version`, {
+      encoding: "utf-8",
+    });
+    console.log("checking env compiler");
+    console.log(o);
+    return true;
+  } catch (e) {
+    console.log(e);
+    return false;
+  }
+}
+exports.checkEnvCompiler = checkEnvCompiler;
+
 /**
  * Ensures the ocaml folder exists at the root of the project, either from the submodule,
  * or by extracting the vendor/ocaml.tar.gz there

scripts/ciTest.js

@@ -42,15 +42,19 @@ if (all) {
 }
 
 function init() {
-  var vendorOCamlPath = path.join(
-    __dirname,
-    "..",
-    "native",
-    require("./buildocaml.js").getVersionPrefix(),
-    "bin"
-  );
-
-  process.env["PATH"] = vendorOCamlPath + path.delimiter + process.env["PATH"];
+  if (!require("./buildocaml.js").checkEnvCompiler()) {
+    // No compiler available on path.
+    // Assume that we built the compiler from source beforehand and add it to the path.
+    var vendorOCamlPath = path.join(
+      __dirname,
+      "..",
+      "native",
+      require("./buildocaml.js").getVersionPrefix(),
+      "bin"
+    );
+
+    process.env["PATH"] = vendorOCamlPath + path.delimiter + process.env["PATH"];
+  }
 
   var ninjaPath = path.join(__dirname, "..", process.platform, "ninja.exe");
 

scripts/install.js

@@ -178,25 +178,6 @@ o all: phony runtime others $stdlib
   console.log("Build finished");
 }
 
-/**
- * works only on *unix
- * used for dev environment or our prebuilt compiler
- * does not work for such version
- * @returns {boolean}
- */
-function checkEnvCompiler() {
-  try {
-    var o = child_process.execSync(`ocamlopt.opt -version`, {
-      encoding: "utf-8",
-    });
-    console.log("checking env compiler");
-    console.log(o);
-    return true;
-  } catch (e) {
-    console.log(e);
-    return false;
-  }
-}
 /**
  * @returns {string}
  */
@@ -207,7 +188,7 @@ function provideCompiler() {
   } else {
     var ocamlopt = "ocamlopt.opt";
     myVersion = "4.06.1";
-    if (!checkEnvCompiler()) {
+    if (!require("./buildocaml.js").checkEnvCompiler()) {
       // no compiler available
       var prefix = require("./buildocaml.js").build(true);
       ocamlopt=`${prefix}/bin/${ocamlopt}`