Made config.headings optional to be able to log only the data 🛰 (#5)

README.md

@@ -2,22 +2,20 @@
 
 Space Log is a simple function which logs tabular data, similar to that of `yarn outdated`.
 
-You could - and probably should - just use `console.table` unless you appreciate a borderless display of data.
-
 ![Regions of Japan](https://github.com/01taylop/space-log/blob/main/assets/results.png?raw=true)
 
 ## How to use Space Log?
 
 Space Log exposes a function, `spaceLog`, which can be imported as a named or default export. Both commonJS and ESM are supported.
 
-The `spaceLog` function expects two arguments; config and data.
+The `spaceLog` function has two arguments;
 
 - `config.columnKeys`: An array of keys, i.e. the `data[key]` of each column.
 
-- `config.headings`: An array of headings, i.e. the title of each column.
+- `config.headings`: An optional array of headings, i.e. the title of each column. If no headings are provided, only the data will be output.
 
 - `data`: An array of objects containing the data to log.
-  - A "theme" can be provided for a given key in a row by adding a property in the format `${key}Theme`. For example, to indicate that the most populous region of Japan is Kantō, `populationTheme` uses [chalk](https://www.npmjs.com/package/chalk) to render green text.
+  - A "theme" can be provided for a corresponding key by adding a property in the format `${key}Theme`. In the code below, `populationTheme` uses [chalk](https://www.npmjs.com/package/chalk) to render green text to indicate that the most populous region of Japan is Kantō.
 
 ```js
 import chalk from chalk

package.json

@@ -1,7 +1,7 @@
 {
   "name": "space-log",
   "description": "A simple utility for logging tabular data to the terminal.",
-  "version": "1.0.1",
+  "version": "1.1.0",
   "type": "module",
   "main": "./lib/index.cjs",
   "exports": {
@@ -26,13 +26,13 @@
     "chalk": "4.1.2"
   },
   "devDependencies": {
-    "@babel/cli": "7.17.10",
-    "@babel/core": "7.17.10",
-    "@babel/plugin-proposal-optional-chaining": "7.16.7",
-    "@babel/plugin-transform-modules-commonjs": "7.17.9",
-    "@babel/preset-env": "7.17.10",
-    "babel-jest": "28.1.0",
-    "jest": "28.1.0",
+    "@babel/cli": "7.19.3",
+    "@babel/core": "7.20.2",
+    "@babel/plugin-proposal-optional-chaining": "7.18.9",
+    "@babel/plugin-transform-modules-commonjs": "7.19.6",
+    "@babel/preset-env": "7.20.2",
+    "babel-jest": "29.3.1",
+    "jest": "29.3.1",
     "rimraf": "3.0.2"
   },
   "author": "Patrick Taylor <hello@patricktaylor.dev>",

src/index.mjs

@@ -6,26 +6,32 @@ const spaceLog = (config, data) => {
   try {
     const { columnKeys, headings } = config
 
+    const hasHeadings = !!(headings && headings.length)
+
     // Intentional Spacing
-    console.log('')
+    if (hasHeadings) {
+      console.log('')
+    }
 
     // Calculate Column Width
     const columnWidths = {}
 
     columnKeys.forEach((key, index) => {
-      const headingLength = headings[index]?.length || defaultHeading.length
+      const headingLength = hasHeadings ? (headings[index]?.length || defaultHeading.length) : 0
       const dataLengths = data.map(item => item[key]?.length || 0)
 
       columnWidths[key] = Math.max(headingLength, ...dataLengths) + 1
     })
 
     // Log Headings
-    const headingLine = columnKeys.map((key, index) => {
-      const title = headings[index] || defaultHeading
-      const spacing = columnWidths[key] - title.length
-      return `${chalk.underline(title)}${' '.repeat(spacing)}`
-    }).join('')
-    console.log(headingLine.trim())
+    if (hasHeadings) {
+      const headingLine = columnKeys.map((key, index) => {
+        const title = headings[index] || defaultHeading
+        const spacing = columnWidths[key] - title.length
+        return `${chalk.underline(title)}${' '.repeat(spacing)}`
+      }).join('')
+      console.log(headingLine.trim())
+    }
 
     // Log Data
     data.forEach(item => {
@@ -41,7 +47,9 @@ const spaceLog = (config, data) => {
     })
 
     // Intentional Spacing
-    console.log('')
+    if (hasHeadings) {
+      console.log('')
+    }
   } catch (error) {
     console.error(error.message)
   }

tests/index.spec.mjs

@@ -10,6 +10,46 @@ describe('spaceLog', () => {
   const mockedErrorLog = jest.spyOn(console, 'error').mockImplementation(text => text)
   const mockedInfoLog = jest.spyOn(console, 'info').mockImplementation(text => text)
 
+  const testData = [{
+    capital: 'Brasília',
+    country: 'Brazil',
+    flag: '🇧🇷'
+  }, {
+    capital: 'Tokyo',
+    country: 'Japan',
+    flag: '🇯🇵'
+  }, {
+    capital: 'Seoul',
+    country: 'South Korea',
+    flag: '🇰🇷'
+  }]
+
+  it('should log a spaced table with headings', () => {
+    spaceLog({
+      columnKeys: ['country', 'capital', 'flag'],
+      headings: ['Country', 'Capital', 'Flag'],
+    }, testData)
+
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(1, '')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(2, '_Country_     _Capital_  _Flag_')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(3, 'Brazil      Brasília 🇧🇷')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(4, 'Japan       Tokyo    🇯🇵')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(5, 'South Korea Seoul    🇰🇷')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(6, '')
+    expect(mockedConsoleLog).toHaveBeenCalledTimes(6)
+  })
+
+  it('should log a spaced table without headings', () => {
+    spaceLog({
+      columnKeys: ['country', 'capital', 'flag'],
+    }, testData)
+
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(1, 'Brazil      Brasília 🇧🇷')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(2, 'Japan       Tokyo    🇯🇵')
+    expect(mockedConsoleLog).toHaveBeenNthCalledWith(3, 'South Korea Seoul    🇰🇷')
+    expect(mockedConsoleLog).toHaveBeenCalledTimes(3)
+  })
+
   it('should log the data for the given config', () => {
     const data = [{
       bar: 'Bar1',