Export text telemetry values to CSV

server/package.json

@@ -7,7 +7,8 @@
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
     "start": "node main.js",
-    "make": "npm i -g pkg && pkg . && chmod -R 777 build"
+    "make": "npm i -g pkg && pkg . && chmod -R 777 build",
+    "test:csv": "node test/session-csv.test.js"
   },
   "author": "",
   "license": "MIT",

server/test/session-csv.test.js

@@ -0,0 +1,75 @@
+const assert = require("assert");
+const fs = require("fs");
+const path = require("path");
+const vm = require("vm");
+
+const www = path.join(__dirname, "..", "www");
+
+const uPlot = {
+    join: tables => {
+        const timestamps = Array.from(new Set(tables.flatMap(table => table[0]))).sort((a, b) => a - b);
+        return [timestamps].concat(tables.map(table => {
+            const values = new Map(table[0].map((timestamp, index) => [timestamp, table[1][index]]));
+            return timestamps.map(timestamp => values.has(timestamp) ? values.get(timestamp) : null);
+        }));
+    }
+};
+
+function exportCSV(app) {
+    let savedFile;
+    const context = {
+        app,
+        uPlot,
+        saveFile: (content, name) => { savedFile = { content, name }; },
+        buildFileName: (name, extension) => `${name}.${extension}`,
+        module: { exports: {} }
+    };
+
+    vm.runInNewContext(
+        `${fs.readFileSync(path.join(www, "utils", "import_export", "session.js"), "utf8")}\nmodule.exports = exportSessionCSV;`,
+        context
+    );
+    context.module.exports();
+    return savedFile;
+}
+
+const defaultExportApp = {
+    csvCellSeparator: ",",
+    csvDecimalSeparator: ".",
+    csvExportView: true,
+    telemetries: {
+        temperature: { type: "default", unit: "C", data: [[1000, 2000], [20.5, 21.5]] },
+        state: { type: "text", data: [[1500, 2500], ["warming", 'ready, "steady"']] }
+    }
+};
+const defaultExport = exportCSV(defaultExportApp);
+
+assert.strictEqual(defaultExport.name, "session.csv");
+assert.strictEqual(defaultExportApp.csvExportView, false);
+assert.strictEqual(defaultExport.content, [
+    "timestamp(ms),temperature (C),state,",
+    '"1000","20.5",,',
+    '"1500",,"warming",',
+    '"2000","21.5",,',
+    '"2500",,"ready, ""steady""",',
+    ""
+].join("\n"));
+
+const commaDecimalExport = exportCSV({
+    csvCellSeparator: ";",
+    csvDecimalSeparator: ",",
+    csvExportView: true,
+    telemetries: {
+        temperature: { type: "default", data: [[1000], [20.5]] },
+        display: { type: "text", data: [[1000], ["3.14"]] },
+        invalid: { type: "default", data: [[1000], [NaN]] }
+    }
+});
+
+assert.strictEqual(commaDecimalExport.content, [
+    "timestamp(ms);temperature;display;invalid;",
+    '"1000";"20,5";"3.14";;',
+    ""
+].join("\n"));
+
+console.log("CSV export preserves text values, CSV quoting, and numeric decimal formatting");

server/www/utils/import_export/session.js

@@ -21,6 +21,21 @@ function getFormatedSerieUnit(dataSerie)
     return "";
 } 
 
+function formatCSVValue(value) {
+    if (value == null) {
+        return "";
+    }
+
+    if (typeof value == "number") {
+        if (!Number.isFinite(value)) {
+            return "";
+        }
+        value = ("" + value).replace(".", app.csvDecimalSeparator);
+    }
+
+    return '"' + ("" + value).replace(/"/g, '""') + '"';
+}
+
 function exportSessionCSV() {
 
     let csv = "timestamp(ms)"+app.csvCellSeparator;
@@ -39,11 +54,7 @@ function exportSessionCSV() {
     for(let i=0;i<joinedData[0].length;i++) {
         for(let j=0;j<joinedData.length;j++) {
             let value = joinedData[j][i];
-            if(isFinite(value) && !isNaN(value)) {
-                valueStr = (""+joinedData[j][i]).replace('.',',').replace(',',app.csvDecimalSeparator)
-                csv += '"'+valueStr+'"';
-
-            }
+            csv += formatCSVValue(value);
             csv += app.csvCellSeparator
         }
         csv += "\n";
@@ -98,4 +109,4 @@ function importSessionJSON(event) {
         }
     };
     reader.readAsText(file);
-}
+}