Add JSON output option in CLI

README.md

@@ -16,18 +16,20 @@ doiuse --browsers "ie >= 9, > 1%, last 2 versions" main.css
 ```
 **Sample output:**
 ```
-/projects/website/main.css: line 5, col 3 - CSS3 Box-sizing not supported by: IE (8,9,10,11), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10,11)
-/projects/website/main.css: line 6, col 3 - CSS3 Box-sizing not supported by: IE (8,9,10,11), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10,11)
-/projects/website/main.css: line 8, col 3 - CSS user-select: none not supported by: IE (8,9)
-/projects/website/main.css: line 9, col 3 - CSS user-select: none not supported by: IE (8,9)
-/projects/website/main.css: line 10, col 3 - CSS user-select: none not supported by: IE (8,9)
-/projects/website/main.css: line 11, col 3 - CSS user-select: none not supported by: IE (8,9)
-/projects/website/main.css: line 12, col 3 - CSS user-select: none not supported by: IE (8,9)
-/projects/website/main.css: line 13, col 3 - Pointer events not supported by: IE (8,9,10), Firefox (32,33), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10)
-/projects/website/main.css: line 14, col 3 - Pointer events not supported by: IE (8,9,10), Firefox (32,33), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10)
-/projects/website/main.css: line 32, col 3 - CSS3 Transforms not supported by: IE (8)
+/projects/website/main.css:5:3: CSS3 Box-sizing not supported by: IE (8,9,10,11), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10,11)
+/projects/website/main.css:6:3: CSS3 Box-sizing not supported by: IE (8,9,10,11), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10,11)
+/projects/website/main.css:8:3: CSS user-select: none not supported by: IE (8,9)
+/projects/website/main.css:9:3: CSS user-select: none not supported by: IE (8,9)
+/projects/website/main.css:10:3: CSS user-select: none not supported by: IE (8,9)
+/projects/website/main.css:11:3: CSS user-select: none not supported by: IE (8,9)
+/projects/website/main.css:12:3: CSS user-select: none not supported by: IE (8,9)
+/projects/website/main.css:13:3: Pointer events not supported by: IE (8,9,10), Firefox (32,33), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10)
+/projects/website/main.css:14:3: Pointer events not supported by: IE (8,9,10), Firefox (32,33), Chrome (36,37,38), Safari (8,7.1), Opera (24,25), iOS Safari (8,7.1,8.1), Android Browser (4.1,4.4,4.4.4), IE Mobile (10)
+/projects/website/main.css:32:3: CSS3 Transforms not supported by: IE (8)
 ```
 
+Use `--json` to get output as (newline-delimited) JSON objects.
+
 
 ## JS
 ```javascript
@@ -53,14 +55,14 @@ Refer to the data in /src/data/features.coffee.
   value matches one of those values.
 
 TODO:
-- [ ] Support @-rules
+- [x] Support @-rules
 - [ ] Allow each feature to have multiple instances of the match criteria laid
-      out above, so that different, disjoint (property, value) combinations can
-      be used to detect a feature.
+  out above, so that different, disjoint (property, value) combinations can
+  be used to detect a feature.
 - [ ] Subfeatures, in to allow a slightly looser coupling with caniuse-db's
-      structure (for handling, e.g., partial support, the different flexbox versions, etc.)
+  structure (for handling, e.g., partial support, the different flexbox versions, etc.)
 - [ ] Prefix-aware testing: i.e., pass along a list of prefixes used with a
-      given feature.  (This is low priority: just use autoprefixer.)
+  given feature.  (This is low priority: just use autoprefixer.)
 
 
 # API Details: 

cli.js

@@ -28,21 +28,31 @@ var yargs = require('yargs')
     description: 'Verbose output. Multiple levels available.'
   })
   .count('verbose')
+  .options('j', {
+    alias: 'json',
+    description: 'Output JSON instead of string linter-like messages.'
+  })
+  .boolean('j')
   .help('h', 'Show help message.')
   .alias('h', 'help');
 
 var argv = yargs.argv;
 
+// Callback to report each unsupported feature usage.
+function report(usageInfo) {
+  console.log(argv.json ? JSON.stringify(usageInfo) : usageInfo.message);
+}
+
 
-var report = console.log.bind(console);
+// Set up the linter instance
 var linter = doiuse({
   browserSelection: argv.b.split(',').map(function(s){return s.trim();}),
-  onUnsupportedFeatureUse: function(usageInfo) {
-    report(usageInfo.message);
-  }
+  onUnsupportedFeatureUse: report
 });
 var processor = postcss(linter);
 
+
+
 // Informational output
 if(argv.l) { argv.v = ++argv.verbose; }
 if(argv.verbose >= 1) {