mongo/jstests/core/explain_writecmd_nonexistent_collection.js

// Test explaining a delete command against a non-existent collection.
//
// @tags: [requires_non_retryable_writes, requires_fastcount,
// assumes_no_implicit_collection_creation_after_drop]
(function() {
    "use strict";

    load("jstests/libs/analyze_plan.js");

    function assertCollectionDoesNotExist(collName) {
        const collectionList = db.getCollectionInfos({name: collName});
        assert.eq(0, collectionList.length, collectionList);
    }

    const collName = "explain_delete_nonexistent_collection";
    const coll = db[collName];
    coll.drop();

    // Explain of delete against a non-existent collection returns an EOF plan.
    let explain = assert.commandWorked(
        db.runCommand({explain: {delete: collName, deletes: [{q: {a: 1}, limit: 0}]}}));
    assert(planHasStage(db, explain.queryPlanner.winningPlan, "EOF"), explain);
    assert(!planHasStage(db, explain.queryPlanner.winningPlan, "DELETE"), explain);

    assertCollectionDoesNotExist(collName);

    // Explain of an update with upsert:false returns an EOF plan.
    explain = assert.commandWorked(db.runCommand(
        {explain: {update: collName, updates: [{q: {a: 1}, u: {$set: {b: 1}}, upsert: false}]}}));
    assert(planHasStage(db, explain.queryPlanner.winningPlan, "EOF"), explain);
    assert(!planHasStage(db, explain.queryPlanner.winningPlan, "UPDATE"), explain);
    assertCollectionDoesNotExist(collName);

    // Explain of an update with upsert:true returns an EOF plan, and does not create a collection.
    explain = assert.commandWorked(db.runCommand(
        {explain: {update: collName, updates: [{q: {a: 1}, u: {$set: {b: 1}}, upsert: true}]}}));
    assert(planHasStage(db, explain.queryPlanner.winningPlan, "EOF"), explain);
    assert(!planHasStage(db, explain.queryPlanner.winningPlan, "UPDATE"), explain);
    assertCollectionDoesNotExist(collName);
}());