I am currently using sql.js to view my database:
async function sqliteRun () { // eslint-disable-line
const SQL = await initSqlJs({
locateFile: () => 'misc/sql-wasm.wasm'
})
const db = new SQL.Database('public/misc/test.sqlite')
const stmt = db.prepare('SELECT * FROM test')
while (stmt.step()) { //
const row = stmt.getAsObject()
console.log('Here is a row: ' + JSON.stringify(row))
}
}
But then I am getting an error: "File is not a database". I double checked my file and it seems correct (I was able to view it in a sqlite file browser)
I also tried using .db and .sql, all give out the same error.
I prefer to load the file directly in the new SQL.Database() constructor. I wont be able to use fs. Any thoughts on how to do this?
Related
Hi,
I have an app on node.js which consists of a single file app.js that looks like this:
//variables
app = require("express")();
//many more variables here
//functions
function dosomething {}
//many more functions here
but since its getting a little too long I would like to break it into several files, one for variables only (variables.js) and another one for functions only (functions.js) and load them from app.js like this like when you do it with php
//variables
include(variables.js);
//functions
include(functions.js);
is it even possible to do that? Or I have to include everything in one single file like I do now?
Thank you.
You can use Module.Export to export a separate file, and import it into another file using the require statement. Please check here for details:
https://www.geeksforgeeks.org/import-and-export-in-node-js/
Happy Learning :-)
Importing API Endpoints
You can do this by using app.use(...) and point each endpoint to a specific file like so:
const express = require("express");
const app = express();
// User Functions
app.use("/api/user", require("./routes/api/user"));
//Orders functions
app.use("/api/orders/", require("./routes/api/orders"));
/**
* Express Server Init
*/
const PORT = process.env.PORT || 5000;
app.listen(PORT, () => console.log(`Server started on ${PORT}`));
Then in /routes/api/user/user.js you would have something like:
const express = require("express");
const router = express.Router();
router.post("/create", (req, res) => {
try {
// Create user
} catch (error) {
console.log(error);
res.sendStatus(500);
}
});
module.exports = router;
Add and index.js inside /routes/api/user to point at the user file to keep things pretty when importing (otherwise you have to import it like /routes/api/user/user):
const user = require("./user");
module.exports = user;
Importing Single File
Not sure your use case but variables could be a bad naming convention since these values are more like constants than variables. Either way, you create it like this:
const variables = {
varibleOne: "valueOne",
varibleTwo: "valueTwo",
varibleThree: "valueThree",
};
module.exports = variables;
Then wherever you want to import it you can do:
const variables = require("./variables");
and access it like so variables.variableOneand so on.
Importing functions
You can also import different functions, say you need a file called helper.js where these are commonly functions needed all over you app, you could do something like this:
const twoDecimals = (number, decimal = ",") => {
let val = (Math.round(number * 100) / 100).toFixed(2);
return decimal === "." ? val : val.replace(".", decimal);
};
const getRandomInt = (max) => {
return Math.floor(Math.random() * Math.floor(max));
};
module.exports = { twoDecimals, getRandomInt };
Then wherever you needed you can import it by:
const { twoDecimals } = require("helper.js");
Now you have access to your helper functions anywhere.
You should get help from the JavaScript modular system (preferably COMMONJS).
For example, suppose we have two files:
1-module.js 2-app.js
So now let's create this files
module.js
let name = "hello world";
function printSomething(message) {
console.log(message)
}
//here export all function and variable
module.exports.name = name;
module.exports.printSomething = printSomething
ok so Well now it is enough that "require" this file in main file :
main.js
// we
const {name, printSomething} = require("./module.js");
printSomething(name);
for export all variable You need to create an object and specify your variables as a property:
let host = "localhost"
let dbname = "laravel_8"
let username = "root"
let password = "root"
function doSomething() {
console.log("hello");
}
module.exports = {host, dbname, username, password, doSomething}
so in main file :
const variables = require("./module.js")
//host
let host = variables.host
//dbname
let dbname = variables.dbname
//function doSomething
let doSomething = variables.doSomething;
doSomething()
// or directly
variables.doSomething()
In fact, in php we use the "->" symbol to access properties, and in JavaScript we use "."
I have a test like this, but i can not get the 'sharedMap' in 'sharedSeq1' value, i don't know how to get the 'remoteFluidObjectHandle' value.
import {MockContainerRuntimeFactory, MockFluidDataStoreRuntime, MockStorage} from "#fluidframework/test-runtime-utils";
import {SharedObjectSequence, SharedObjectSequenceFactory} from "#fluidframework/sequence";
import * as mocks from "#fluidframework/test-runtime-utils";
import {SharedMap} from "#fluidframework/map";
import {IFluidHandle} from "#fluidframework/core-interfaces";
const mockRuntime: mocks.MockFluidDataStoreRuntime = new mocks.MockFluidDataStoreRuntime();
describe('ShredObjectSequence', function () {
it('should get synchronization data from another shared object', async function () {
const dataStoreRuntime1 = new MockFluidDataStoreRuntime();
const sharedSeq1: SharedObjectSequence<IFluidHandle<SharedMap>> = new SharedObjectSequence(mockRuntime, 'shareObjectSeq1', SharedObjectSequenceFactory.Attributes,)
const containerRuntimeFactory = new MockContainerRuntimeFactory();
dataStoreRuntime1.local = false;
const containerRuntime1 = containerRuntimeFactory.createContainerRuntime(
dataStoreRuntime1,
);
const services1 = {
deltaConnection: containerRuntime1.createDeltaConnection(),
objectStorage: new MockStorage(),
};
sharedSeq1.initializeLocal();
sharedSeq1.connect(services1);
const dataStoreRuntime2 = new MockFluidDataStoreRuntime();
const containerRuntime2 = containerRuntimeFactory.createContainerRuntime(
dataStoreRuntime2,
);
const services2 = {
deltaConnection: containerRuntime2.createDeltaConnection(),
objectStorage: new MockStorage(),
};
const sharedSeq2: SharedObjectSequence<IFluidHandle<SharedMap>> = new SharedObjectSequence(mockRuntime, 'shareObjectSeq2', SharedObjectSequenceFactory.Attributes,)
sharedSeq2.initializeLocal();
sharedSeq2.connect(services2);
// insert a node into sharedSeq2, it will sync to sharedSeq1
sharedSeq2.insert(0, [<IFluidHandle<SharedMap>>new SharedMap('sharedMapId', mockRuntime, SharedMap.getFactory().attributes).handle])
containerRuntimeFactory.processAllMessages();
// next case is passed, it show we got the sharedSeq2 changed
expect(sharedSeq1.getLength()).toBe(1)
const remoteFluidObjectHandle = await sharedSeq1.getRange(0, 1)[0];
// at here, i get error: Cannot read property 'mimeType' of null, it cause by remoteFluidObjectHandle.ts:51:30
const sharedMap = await remoteFluidObjectHandle.get()
expect(sharedMap).not.toBeUndefined()
});
});
run this test will get 'Cannot read property 'mimeType' of null' error, it caused by 'remoteFluidObjectHandle.ts:51:30'
The fluid mocks have very limited and specific behaviors, it looks like you are hitting the limits of them. You'll have better luck with an end-to-end test, see packages\test\end-to-end-tests. These use the same in-memory server as our as the playground on fluidframework dot com. The in-memory server uses the same code as tinylicious, our single process server and routerlicious, our docker based reference implementation.
I have the following code:
NOTE getDb() is wrapper around admin.firestore() see the link in the end of the question for more details.
let wordRef = await getDb().
.collection(DOC_HAS_WORD_COUNT)
.doc(word)
await wordRef.set({ word: word, 'count': 0 })
await wordRef.update('count', admin.firestore.FieldValue.increment(1))
When I execute it I get
FirebaseError: Function DocumentReference.update() called with invalid data. Unsupported field value: a custom object (found in field count)
How do I increment the value in node js, firestore, cloud functions?
NOTE: this problem is specific to Mocha testing, I didn't check but it will probably not fail on real env.
The problem is caused by the code using the real implementation in test, which need to be override by an emulator implementation, as explain in:
https://claritydev.net/blog/testing-firestore-locally-with-firebase-emulators/
Where u can also find the definition of getDb() I used in the code snipet
The following code will replace the firebase admin at run time, only when running in test env.
NOTE: this code is based on https://claritydev.net/blog/testing-firestore-locally-with-firebase-emulators/
and for a full solution, one need to do the same trick for db as explained in the link
//db.js
const admin = require("firebase-admin");
let firebase;
if (process.env.NODE_ENV !== "test") {
firebase = admin
}
exports.getFirebase = () => {
return firebase;
};
exports.setFirebase = (fb) => {
firebase = fb;
};
test:
// package.test.js
process.env.NODE_ENV = "test"
beforeEach(() => {
// Set the emulator firebase before each test
setFirebase(firebase)
});
import:
// package.test.js and package.js (at the top)
const { setFirebase } = require("../db.js")
code:
// package.js
let wordRef = await getDb()
.collection(DOC_HAS_WORD_COUNT)
.doc(word)
await wordRef.set({ word: word, 'count': 0 })
await wordRef.update('count', getFirebase().firestore.FieldValue.increment(1))
I have this async function in a file called index.main.js which has a variable , 'targetFiles' which I would like to export to another file which is index.js. Problem is I can't find a way to export the value of this particular variable without getting "undefined" as a result.
I have tried implementing promise, callback , export default function, and doing countless hours of research to no avail.
//this code is in index.main.js
var targetFiles = "";
async function listFilesInDepth()
{
const {Storage} = require('#google-cloud/storage');
const storage = new Storage();
const bucketName = 'probizmy';
const [files] = await storage.bucket(bucketName).getFiles();
console.log('List Of Files Available:');
files.forEach(file =>
{
targetFiles = file.name; //this is the variable to export
console.log(`-----`+file.name);
});
return targetFiles;
}
module.exports = {
fn : targetFiles
}
trying to export the value to index.js is either empty or "undefined"
//this is the code in index.js
const a = require('./index.main');
console.log(a.fn); //undefined or empty
The expected value that should be the output is the value of targetFiles. Let's say if targetFiles is abc12345.JSON in the async function,the console.log in index.js should be of that value.
I'm hoping someone could give me some insight on how I could overcome this issue. Thank you in advance :)
Following solution might help you, but not sure for your use case. (Not using module-exports):
You can use request-context package to achieve same functionality.
What is package does is, you can set the value(data) against a key and then access the same in the following code execution within the same context.
Run npm install request-context
In your main app.js (server file), register the request-context as a middleware.
const contextService = require("request-context");
const app = express();
...
// Multiple contexts are supported, but below we are setting for per request.
app.use(contextService.middleware("request"));
...
And then in your index.main.js, once targetFiles is ready, set the targetFiles into request context.
const contextService = require("request-context");
...
files.forEach(file =>
{
targetFiles = file.name; //this is the variable to export
console.log(`-----`+file.name);
});
// Here `Request` is the namespace(context), targetFileKey is the key and targetFiles is the value.
contextService.set("request:targetFileKey", targetFiles);
return targetFiles;
}
...
And in the same request, where you wanna use targetFile, you can do the following:
index.js (Can be any file where you need targetFiles after being set):
const contextService = require("request-context");
...
// Reading from same namespace request to which we had set earlier
const targetFiles = contextService.get("request:targetFileKey");
...
Please note:
You will be able to access targetFiles in the same request you set. That means, request-context we configured in app.js is per API request, meaning, in every API request, you have to set it before reading.
Please let me know if the above solution doesn't fit for you.
I'm trying to generate a json file containing the filenames of all the files in a certain directory. I need this to create a cheatsheet for icons.
Currently I'm trying to run a script locally via terminal, to generate the json. That json will be the input for a react component that will display icons. That component works, the create json script doesn't.
Code for generating the json
const fs = require('fs');
const path = require('path');
/**
* Create JSON file
*/
const CreateJson = () => {
const files = [];
const dir = '../icons';
fs.readdirSync(dir).forEach(filename => {
const name = path.parse(filename);
const filepath = path.resolve(dir, filename);
const stat = fs.statSync(filepath);
const isFile = stat.isFile();
if (isFile) files.push({ name });
});
const data = JSON.stringify(files, null, 2);
fs.writeFileSync('../Icons.json', data);
};
module.exports = CreateJson;
I run it in terminal using
"create:json": "NODE_ENV=build node ./scripts/CreateJson.js"
I expect a json file to be created/overridden. But terminal returns:
$ NODE_ENV=build node ./scripts/CreateJson.js
✨ Done in 0.16s.
Any pointers?
You are creating a function CreateJson and exporting it, but you are actually never calling it.
You can get rid of the module.exports and replace it with CreateJson().
When you'll execute the file with node, it will see the function declaration, and a call to it, whereas with your current code there is no call.