docs(csv-parse): new cast sample

Author: wdavidw

packages/csv-parse/samples/option.cast.context.js

@@ -0,0 +1,36 @@
+
+import assert from 'node:assert';
+import { parse } from 'csv-parse/sync';
+
+const data = `
+  2000-01-01,date1
+  2050-11-27,date2
+`.trim();
+const records = parse(data, {
+  // The cast option exect a function which 
+  // is called with two arguments,
+  // the parsed value and a context object
+  cast: function(value, context){
+    // You can return any value
+    if(context.index === 0){
+      // Such as a string
+      return `${value}T05:00:00.000Z`;
+    }else{
+      // Or the `context` object literal
+      return context;
+    }
+  },
+  trim: true
+});
+assert.deepStrictEqual(records, [
+  [ '2000-01-01T05:00:00.000Z', {
+    bytes: 16, comment_lines: 0, empty_lines: 0, invalid_field_length: 0,
+    lines: 1, records: 0, columns: false, error: undefined, header: false,
+    index: 1, column: 1, quoting: false, raw: undefined
+  } ],
+  [ '2050-11-27T05:00:00.000Z', {
+    bytes: 35, comment_lines: 0, empty_lines: 0, invalid_field_length: 0,
+    lines: 2, records: 1, columns: false, error: undefined, header: false,
+    index: 1, column: 1, quoting: false, raw: undefined
+  } ]
+]);

packages/csv-parse/samples/option.cast.js

@@ -1,36 +1,31 @@
 
-import assert from 'node:assert';
-import { parse } from 'csv-parse/sync';
+import assert from "node:assert";
+import { parse } from "csv-parse/sync";
 
 const data = `
-  2000-01-01,date1
-  2050-11-27,date2
+  1,2,3
+  4,5,6
 `.trim();
 const records = parse(data, {
-  // The cast option exect a function which 
+  // The cast option exect a function which
   // is called with two arguments,
   // the parsed value and a context object
-  cast: function(value, context){
-    // You can return any value
-    if(context.index === 0){
-      // Such as a string
-      return `${value}T05:00:00.000Z`;
-    }else{
-      // Or the `context` object literal
-      return context;
+  cast: function (value, context) {
+    // Index indicates the column position
+    if (context.index === 0) {
+      // Return the value untouched
+      return value;
+    } else if (context.index === 1) {
+      // Convert the value to a string
+      return parseInt(value);
+    } else {
+      // Return a different value
+      return `Value is ${value}`
     }
   },
-  trim: true
+  trim: true,
 });
 assert.deepStrictEqual(records, [
-  [ '2000-01-01T05:00:00.000Z', {
-    bytes: 16, comment_lines: 0, empty_lines: 0, invalid_field_length: 0,
-    lines: 1, records: 0, columns: false, error: undefined, header: false,
-    index: 1, column: 1, quoting: false, raw: undefined
-  } ],
-  [ '2050-11-27T05:00:00.000Z', {
-    bytes: 35, comment_lines: 0, empty_lines: 0, invalid_field_length: 0,
-    lines: 2, records: 1, columns: false, error: undefined, header: false,
-    index: 1, column: 1, quoting: false, raw: undefined
-  } ]
+  [ "1", 2, "Value is 3" ],
+  [ "4", 5, "Value is 6" ],
 ]);