Add support for minWords as a setting

Author: wooorm

Diff for: index.js

@@ -32,6 +32,7 @@ var spacheFormula = require('spache-formula');
  */
 
 var DEFAULT_TARGET_AGE = 16;
+var WORDYNESS_THRESHOLD = 5;
 var SURENESS_THRESHOLD = 4 / 7;
 var SURENESS_THRESHOLD_VERY = 5 / 7;
 var SURENESS_THRESHOLD_DEFINITELY = 6 / 7;
@@ -132,6 +133,11 @@ function attacher(processor, options) {
     var settings = options || {};
     var targetAge = settings.age || DEFAULT_TARGET_AGE;
     var threshold = settings.threshold || SURENESS_THRESHOLD;
+    var minWords = settings.minWords;
+
+    if (minWords === null || minWords === undefined) {
+        minWords = WORDYNESS_THRESHOLD;
+    }
 
     return function (tree, file) {
         /**
@@ -207,6 +213,10 @@ function attacher(processor, options) {
                 }
             });
 
+            if (wordCount < minWords) {
+                return;
+            }
+
             counts = {
                 'complexPolysillabicWord': complexPolysillabicWord,
                 'polysillabicWord': polysillabicWord,

Diff for: readme.md

@@ -93,6 +93,14 @@ Detect possibly hard to read sentences.
         be warned about.  This can be modified by passing in a new
         threshold.
 
+    *   `minWords` (`number`, default: `5`)
+        — Minimum number of words a sentence should have when warning.
+        Most algorithms are designed to take a large sample of
+        sentences to detect the body’s reading level.  This plug-in,
+        however, works on a per-sentence basis.  This makes the results
+        quite skewered when said sentence has, for example, a few long
+        words or some unknown ones.
+
 ## License
 
 [MIT][license] © [Titus Wormer][author]

Diff for: test.js

@@ -146,5 +146,31 @@ test('readability', function (t) {
             );
         });
 
+    retext()
+        .use(readability)
+        .process('Honorificabilitudinitatibus.', function (err, file) {
+            t.ifError(err, 'should not fail (#8)');
+
+            t.deepEqual(
+                file.messages.map(String),
+                [],
+                'should support minWords (default)'
+            );
+        });
+
+    retext()
+        .use(readability, {
+            'minWords': 0
+        })
+        .process('Honorificabilitudinitatibus.', function (err, file) {
+            t.ifError(err, 'should not fail (#8)');
+
+            t.deepEqual(
+                file.messages.map(String),
+                ['1:1-1:29: Quite hard to read sentence'],
+                'should support `minWords` (config)'
+            );
+        });
+
     t.end();
 });