Initial commit

node_modules/execa/lib/ipc/reference.js

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+// By default, Node.js keeps the subprocess alive while it has a `message` or `disconnect` listener.
+// We replicate the same logic for the events that we proxy.
+// This ensures the subprocess is kept alive while `getOneMessage()` and `getEachMessage()` are ongoing.
+// This is not a problem with `sendMessage()` since Node.js handles that method automatically.
+// We do not use `anyProcess.channel.ref()` since this would prevent the automatic `.channel.refCounted()` Node.js is doing.
+// We keep a reference to `anyProcess.channel` since it might be `null` while `getOneMessage()` or `getEachMessage()` is still processing debounced messages.
+// See https://github.com/nodejs/node/blob/2aaeaa863c35befa2ebaa98fb7737ec84df4d8e9/lib/internal/child_process.js#L547
+export const addReference = (channel, reference) => {
+	if (reference) {
+		addReferenceCount(channel);
+	}
+};
+
+const addReferenceCount = channel => {
+	channel.refCounted();
+};
+
+export const removeReference = (channel, reference) => {
+	if (reference) {
+		removeReferenceCount(channel);
+	}
+};
+
+const removeReferenceCount = channel => {
+	channel.unrefCounted();
+};
+
+// To proxy events, we setup some global listeners on the `message` and `disconnect` events.
+// Those should not keep the subprocess alive, so we remove the automatic counting that Node.js is doing.
+// See https://github.com/nodejs/node/blob/1b965270a9c273d4cf70e8808e9d28b9ada7844f/lib/child_process.js#L180
+export const undoAddedReferences = (channel, isSubprocess) => {
+	if (isSubprocess) {
+		removeReferenceCount(channel);
+		removeReferenceCount(channel);
+	}
+};
+
+// Reverse it during `disconnect`
+export const redoAddedReferences = (channel, isSubprocess) => {
+	if (isSubprocess) {
+		addReferenceCount(channel);
+		addReferenceCount(channel);
+	}
+};