fix: Processes.builder(...).withInput(String) not working correctly

Author: sebthom

jstuff-core/src/main/java/net/sf/jstuff/core/io/Processes.java

@@ -154,25 +154,38 @@ public ProcessWrapper start() throws IOException {
             pb.directory(workDir);
          }
 
+         /*
+          * Configure ProcessBuilder redirects that must be set before start().
+          */
+         if (input instanceof final File f) {
+            pb.redirectInput(f);
+         }
+         if (redirectErrorToOutput) {
+            pb.redirectErrorStream(true);
+         } else if (redirectError instanceof final File f) {
+            pb.redirectError(f);
+         }
+         if (redirectOutput instanceof final File f) {
+            pb.redirectOutput(f);
+         }
+
          final Process proc = pb.start();
 
-         if (input != null) {
+         /*
+          * Handle stdin/output redirection that uses the process streams.
+          */
+         if (input != null && !(input instanceof File)) {
             final var input = this.input;
-            if (input instanceof final File f) {
-               pb.redirectInput(f);
-            } else if (input instanceof final InputStream is) {
+            if (input instanceof final InputStream is) {
                writeToStdIn(is, proc);
             } else if (input instanceof final CharSequence cs) {
                writeToStdIn(cs, proc);
             }
          }
-         if (redirectErrorToOutput) {
-            pb.redirectError();
-         } else if (redirectError != null) {
+
+         if (!redirectErrorToOutput && redirectError != null && !(redirectError instanceof File)) {
             final var redirectError = this.redirectError;
-            if (redirectError instanceof final File f) {
-               pb.redirectError(f);
-            } else if (redirectError instanceof final OutputStream os) {
+            if (redirectError instanceof final OutputStream os) {
                redirect(proc.getErrorStream(), os);
             } else if (redirectError instanceof final Appendable appendable) {
                redirect(proc.getErrorStream(), appendable);
@@ -181,11 +194,9 @@ public ProcessWrapper start() throws IOException {
             }
          }
 
-         if (redirectOutput != null) {
+         if (redirectOutput != null && !(redirectOutput instanceof File)) {
             final var redirectOutput = this.redirectOutput;
-            if (redirectOutput instanceof final File f) {
-               pb.redirectOutput(f);
-            } else if (redirectOutput instanceof final OutputStream os) {
+            if (redirectOutput instanceof final OutputStream os) {
                redirect(proc.getInputStream(), os);
             } else if (redirectOutput instanceof final Appendable appendable) {
                redirect(proc.getInputStream(), appendable);
@@ -286,6 +297,7 @@ public Builder withRedirectError(final @Nullable PrintStream target) {
       public Builder withRedirectErrorToOutput() {
          if (redirectError != null)
             throw new IllegalArgumentException("withRedirectErrorToOutput() and withRedirectError() are mutually exclusive.");
+         redirectErrorToOutput = true;
          return this;
       }
 

jstuff-core/src/test/java/net/sf/jstuff/core/io/ProcessesTest.java

@@ -7,6 +7,9 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
@@ -103,4 +106,66 @@ void testProgrammaticTermination() throws IOException, InterruptedException {
       Threads.sleep(1000);
       assertThat(signal.await(5, TimeUnit.SECONDS)).isTrue();
    }
+
+   @Test
+   void testRedirectOutputToFile() throws IOException, InterruptedException {
+      final Path outFile = Files.createTempFile("jstuff-processes-out", ".txt");
+      try {
+         final String exe;
+         final List<String> args;
+         if (SystemUtils.IS_OS_WINDOWS) {
+            exe = "cmd";
+            args = List.of("/c", "echo OUT-FILE");
+         } else {
+            exe = "sh";
+            args = List.of("-c", "echo OUT-FILE");
+         }
+
+         final ProcessWrapper prc = Processes.builder(exe) //
+            .withArgs(args) //
+            .withRedirectOutput(outFile) //
+            .start() //
+            .waitForExit(5, TimeUnit.SECONDS);
+
+         assertThat(prc.getState()).isEqualTo(Processes.ProcessState.SUCCEEDED);
+         assertThat(prc.exitStatus()).isZero();
+
+         final String content = Files.readString(outFile);
+         assertThat(content).contains("OUT-FILE");
+      } finally {
+         Files.deleteIfExists(outFile);
+      }
+   }
+
+   @Test
+   void testRedirectErrorToOutputFile() throws IOException, InterruptedException {
+      final Path outFile = Files.createTempFile("jstuff-processes-errout", ".txt");
+      try {
+         final String exe;
+         final List<String> args;
+         if (SystemUtils.IS_OS_WINDOWS) {
+            exe = "cmd";
+            args = List.of("/c", "echo OUT-LINE & echo ERR-LINE 1>&2");
+         } else {
+            exe = "sh";
+            args = List.of("-c", "echo OUT-LINE; echo ERR-LINE 1>&2");
+         }
+
+         final ProcessWrapper prc = Processes.builder(exe) //
+            .withArgs(args) //
+            .withRedirectErrorToOutput() //
+            .withRedirectOutput(outFile) //
+            .start() //
+            .waitForExit(5, TimeUnit.SECONDS);
+
+         assertThat(prc.getState()).isEqualTo(Processes.ProcessState.SUCCEEDED);
+         assertThat(prc.exitStatus()).isZero();
+
+         final String content = Files.readString(outFile);
+         assertThat(content).contains("OUT-LINE");
+         assertThat(content).contains("ERR-LINE");
+      } finally {
+         Files.deleteIfExists(outFile);
+      }
+   }
 }

pom.xml

@@ -11,7 +11,7 @@
    <parent>
       <groupId>com.vegardit.maven</groupId>
       <artifactId>vegardit-maven-parent</artifactId>
-      <version>6.1.13</version>
+      <version>6.1.14</version>
    </parent>
 
    <groupId>net.sf.jstuff</groupId>