Support clients without stdin support (allow_stdin=false)

.gitignore

@@ -21,6 +21,7 @@ artifacts/
 
 # Project Python virtual environments
 /venv/
+/distrib/venv/
 
 # Jupyter notebooks checkpoints
 **/.ipynb_checkpoints

gradle.properties

@@ -1,5 +1,5 @@
 # kotlinVersion=1.4.255-SNAPSHOT
-kotlinVersion=1.5.0-dev-1206
+kotlinVersion=1.4.30
 kotlinLanguageLevel=1.4
 jvmTarget=1.8
 

src/main/kotlin/org/jetbrains/kotlin/jupyter/connection.kt

@@ -8,6 +8,7 @@ import org.jetbrains.kotlin.utils.addToStdlib.min
 import org.zeromq.SocketType
 import org.zeromq.ZMQ
 import java.io.Closeable
+import java.io.IOException
 import java.security.SignatureException
 import javax.crypto.Mac
 import javax.crypto.spec.SecretKeySpec
@@ -208,3 +209,9 @@ fun ZMQ.Socket.receiveMessage(start: ByteArray, hmac: HMAC): Message? {
         content.parseJson()
     )
 }
+
+object DisabledStdinInputStream : java.io.InputStream() {
+    override fun read(): Int {
+        throw IOException("Input from stdin is unsupported by the client")
+    }
+}

src/main/kotlin/org/jetbrains/kotlin/jupyter/protocol.kt

@@ -394,7 +394,8 @@ fun JupyterConnection.evalWithIO(config: OutputConfig, srcMessage: Message, body
     System.setErr(PrintStream(forkedError, false, "UTF-8"))
 
     val `in` = System.`in`
-    System.setIn(stdinIn)
+    val allowStdIn = srcMessage.content?.boolean("allow_stdin") ?: true
+    System.setIn(if (allowStdIn) stdinIn else DisabledStdinInputStream)
     try {
         return try {
             val exec = body()

src/test/kotlin/org/jetbrains/kotlin/jupyter/test/executeTests.kt

@@ -7,6 +7,7 @@ import org.jetbrains.kotlin.jupyter.get
 import org.jetbrains.kotlin.jupyter.jsonObject
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertNull
+import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.Timeout
 import org.zeromq.ZMQ
@@ -24,6 +25,7 @@ class ExecuteTests : KernelServerTestsBase() {
         hasResult: Boolean = true,
         ioPubChecker: (ZMQ.Socket) -> Unit = {},
         inputs: List<String> = emptyList(),
+        allowStdin: Boolean = true,
     ): Any? {
         val context = ZMQ.context(1)
         val shell = ClientSocket(context, JupyterSockets.shell)
@@ -35,7 +37,7 @@ class ExecuteTests : KernelServerTestsBase() {
             ioPub.connect()
             stdin.connect()
 
-            shell.sendMessage("execute_request", content = jsonObject("code" to code))
+            shell.sendMessage("execute_request", content = jsonObject("code" to code, "allow_stdin" to allowStdin))
             inputs.forEach {
                 stdin.sendMessage("input_reply", jsonObject("value" to it))
             }
@@ -69,6 +71,19 @@ class ExecuteTests : KernelServerTestsBase() {
         }
     }
 
+    private fun testWithNoStdin(code: String) {
+        doExecute(
+            code,
+            hasResult = false,
+            allowStdin = false,
+            ioPubChecker = {
+                val msg = it.receiveMessage()
+                assertEquals("stream", msg.type())
+                assertTrue((msg.content!!["text"] as String).startsWith("java.io.IOException: Input from stdin is unsupported by the client"))
+            }
+        )
+    }
+
     @Test
     fun testExecute() {
         val res = doExecute("2+2") as JsonObject
@@ -153,4 +168,14 @@ class ExecuteTests : KernelServerTestsBase() {
         val res = doExecute(code, inputs = listOf("42"))
         assertEquals(jsonObject("text/plain" to "42"), res)
     }
+
+    @Test
+    fun testReadLineWithNoStdin() {
+        testWithNoStdin("readLine() ?: \"blah\"")
+    }
+
+    @Test
+    fun testStdinReadWithNoStdin() {
+        testWithNoStdin("System.`in`.read()")
+    }
 }