add message option (#376)

README.md

@@ -560,6 +560,9 @@ Each section in the config can have these options:
   Format: `100 B`, `10 kB`, `500 ms`, `1 s`.
 * **name**: the name of the current section. It will only be useful
   if you have multiple sections.
+* **message**: an optional custom message to display additional information,
+  such as guidance for resolving errors, relevant links, or instructions
+  for next steps when a limit is exceeded.
 * **entry**: when using a custom webpack config, a webpack entry could be given.
   It could be a string or an array of strings.
   By default, the total size of all entry points will be checked.

packages/size-limit/create-reporter.js

@@ -135,6 +135,9 @@ function createHumanReporter(process, isSilentMode = false) {
             }
             let diff = formatBytes(check.size - check.sizeLimit)
             print(red(`Package size limit has exceeded by ${diff}`))
+            if (check.message) {
+              print(check.message)
+            }
           } else if (check.highlightLess && check.size < check.sizeLimit) {
             let diff = formatBytes(check.sizeLimit - check.size)
             print(bgGreen(black(`Package size is ${diff} less than limit`)))

packages/size-limit/get-config.js

@@ -21,6 +21,7 @@ let OPTIONS = {
   ignore: ['webpack', 'esbuild'],
   import: ['webpack', 'esbuild'],
   limit: true,
+  message: true,
   modifyEsbuildConfig: 'esbuild',
   modifyWebpackConfig: 'webpack',
   module: true,

packages/size-limit/test/__snapshots__/create-reporter.test.js.snap

@@ -71,6 +71,17 @@ exports[`renders config-less result 1`] = `
 "
 `;
 
+exports[`renders custom message 1`] = `
+"  
+  Package size limit has exceeded by 1 B
+  see docs for additional instructions
+  Size limit: 100 B
+  Size:       101 B brotlied
+  
+  Try to reduce size or increase limit at .size-limit.json
+"
+`;
+
 exports[`renders failed results 1`] = `
 "  
   ok

packages/size-limit/test/create-reporter.test.js

@@ -263,6 +263,24 @@ it('renders single result', () => {
   ).toMatchSnapshot()
 })
 
+it('renders custom message', () => {
+  expect(
+    results(['file'], {
+      checks: [
+        {
+          message: 'see docs for additional instructions',
+          name: 'big fail',
+          passed: false,
+          size: 101,
+          sizeLimit: 100
+        }
+      ],
+      configPath: '.size-limit.json',
+      failed: true
+    })
+  ).toMatchSnapshot()
+})
+
 it('renders config-less result', () => {
   expect(
     results(['time'], {