Change prepack npm script to prepare (take 2) (#1755)

* update truffle to include bugfix

* change prepack script to prepare

* add npx in compile script

* fix for older node

* rename script file to prepare

scripts/compile.sh

@@ -4,7 +4,4 @@ if [ "$SOLC_NIGHTLY" = true ]; then
   docker pull ethereum/solc:nightly
 fi
 
-# Necessary to avoid an error in Truffle
-rm -rf build/contracts
-
-truffle compile
+npx truffle compile

scripts/prepare.js

@@ -22,11 +22,13 @@ const pkgFiles = readJSON('package.json').files;
 // Get only negated patterns.
 const ignorePatterns = pkgFiles
   .filter(pat => pat.startsWith('!'))
-// Add **/* to ignore all files contained in the directories.
-  .flatMap(pat => [pat, path.join(pat, '**/*')])
 // Remove the negation part. Makes micromatch usage more intuitive.
   .map(pat => pat.slice(1));
 
+const ignorePatternsSubtrees = ignorePatterns
+// Add **/* to ignore all files contained in the directories.
+  .concat(ignorePatterns.map(pat => path.join(pat, '**/*')));
+
 const artifactsDir = 'build/contracts';
 
 let n = 0;
@@ -36,7 +38,7 @@ for (const artifact of fs.readdirSync(artifactsDir)) {
   const { sourcePath: fullSourcePath } = readJSON(fullArtifactPath);
   const sourcePath = path.relative('.', fullSourcePath);
 
-  const ignore = match.any(sourcePath, ignorePatterns);
+  const ignore = match.any(sourcePath, ignorePatternsSubtrees);
 
   if (ignore) {
     fs.unlinkSync(fullArtifactPath);