Throw if compilation failed (#39)

* Throw if compilation failed

* Refactor compilation errors handling

---------

Co-authored-by: Oleksandr Yakushev <alex@bytopia.org>

src/virgil/compile.clj

@@ -148,10 +148,13 @@
 (defn compile-all-java
   ([directories] (compile-all-java directories nil false))
   ([directories options verbose?]
-   (let [diag (DiagnosticCollector.)
+   (let [collector (DiagnosticCollector.)
          options (ArrayList. (vec options))
          name->source (generate-classname->source directories)]
      (println "Compiling" (count name->source)"Java source files in" directories "...")
      (binding [*print-compiled-classes* verbose?]
-       (compile-java options diag name->source))
-     (print-diagnostics diag))))
+       (compile-java options collector name->source))
+     (when-let [diags (seq (.getDiagnostics collector))]
+       (print-diagnostics diags)
+       (throw (ex-info (format "Compilation failed: %d error(s)." (count diags))
+                       {:diagnostics diags}))))))

src/virgil/util.clj

@@ -1,6 +1,6 @@
 (ns virgil.util
   "Utilities for cross-tooling."
-  (:import (javax.tools DiagnosticCollector Diagnostic$Kind)))
+  (:import (javax.tools Diagnostic Diagnostic$Kind)))
 
 (defn println-err [& args]
   (binding [*out* *err*]
@@ -15,8 +15,8 @@
     Diagnostic$Kind/MANDATORY_WARNING println-err
     println))
 
-(defn print-diagnostics [^DiagnosticCollector diag-coll]
-  (doseq [d (.getDiagnostics diag-coll)]
+(defn print-diagnostics [diagnostics]
+  (doseq [^Diagnostic d diagnostics]
     (let [k (.getKind d)
           log (infer-print-function k)]
       (if (nil? (.getSource d))