From 8384cff3b1f2946685c991b76a1b5ed1cd01b1a5 Mon Sep 17 00:00:00 2001
From: Alex J Burke <alex@alexjeffburke.com>
Date: Thu, 21 May 2020 12:47:22 +0200
Subject: [PATCH 1/2] Add ncolors argument and use it for a legacy query string
 engine arg.

---
 src/engines/pngquant.js | 11 ++++++++++
 src/queryString.js      |  2 +-
 test/impro.js           | 46 ++++++++++++++++++++++++++++++++++++++++-
 test/queryString.js     |  4 ++--
 4 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/src/engines/pngquant.js b/src/engines/pngquant.js
index 0808e26..81f466b 100644
--- a/src/engines/pngquant.js
+++ b/src/engines/pngquant.js
@@ -8,6 +8,7 @@ module.exports = {
   outputTypes: ['png'],
   operations: [
     'floyd',
+    'ncolors',
     'nofs',
     'ordered',
     'speed',
@@ -23,6 +24,8 @@ module.exports = {
           (args.length === 1 &&
             /^(?:0(?:\.\d+)?|1(?:\.0+)?)$/.test(String(args[0])))
         );
+      case 'ncolors':
+        return args.length === 1 && args[0] >= 2 && args[0] <= 256;
       case 'speed':
         return args.length === 1 && args[0] >= 1 && args[0] <= 11;
       case 'quality':
@@ -37,9 +40,17 @@ module.exports = {
   },
   execute: function(pipeline, operations, options) {
     var commandLineArgs = [];
+    var nColors;
     operations.forEach(operation => {
+      if (operation.name === 'ncolors') {
+        nColors = operation.args[0];
+        return;
+      }
       commandLineArgs.push('--' + operation.name, ...operation.args);
     });
+    if (nColors) {
+      commandLineArgs.push(nColors);
+    }
     commandLineArgs.push('-');
 
     pipeline._attach(new PngQuant(commandLineArgs));
diff --git a/src/queryString.js b/src/queryString.js
index 544947e..0711969 100644
--- a/src/queryString.js
+++ b/src/queryString.js
@@ -120,7 +120,7 @@ function prepareLegacyQueryString(queryString, improInstance) {
           result.push(bit.slice(1));
           lastSeenOptionIndex = index + 1; // account for the engine entry
         } else if (engineName === 'pngquant') {
-          result.push(`speed=${bit}`);
+          result.push(`ncolors=${bit}`);
         } else if (lastSeenOptionIndex > -1) {
           result[lastSeenOptionIndex] += `=${bit}`;
         }
diff --git a/test/impro.js b/test/impro.js
index 69b68ce..2cbd135 100644
--- a/test/impro.js
+++ b/test/impro.js
@@ -1759,7 +1759,7 @@ describe('impro', function() {
       return expect(
         'purplealpha24bit.png',
         'when piped through',
-        impro.pngquant().speed(8),
+        impro.pngquant().ncolors(256),
         'to yield output satisfying',
         expect.it('to have metadata satisfying', {
           format: 'PNG',
@@ -1771,6 +1771,16 @@ describe('impro', function() {
       );
     });
 
+    it('should reject with invalid argument', () => {
+      return expect(
+        () => {
+          impro.jpegtran().ncolors(1);
+        },
+        'to throw',
+        'invalid operation or arguments: ncolors=[1]'
+      );
+    });
+
     it('should support floyd', () => {
       const executeSpy = sinon.spy(impro.engineByName.pngquant, 'execute');
 
@@ -1788,6 +1798,21 @@ describe('impro', function() {
       });
     });
 
+    it('should support ncolors', () => {
+      const executeSpy = sinon.spy(impro.engineByName.pngquant, 'execute');
+
+      impro
+        .pngquant()
+        .ncolors(2)
+        .flush();
+
+      return expect(executeSpy.returnValues[0], 'to equal', [2, '-']).finally(
+        () => {
+          executeSpy.restore();
+        }
+      );
+    });
+
     it('should support posterize', () => {
       const executeSpy = sinon.spy(impro.engineByName.pngquant, 'execute');
 
@@ -1838,6 +1863,25 @@ describe('impro', function() {
         executeSpy.restore();
       });
     });
+
+    it('should support multiple operations', () => {
+      const executeSpy = sinon.spy(impro.engineByName.pngquant, 'execute');
+
+      impro
+        .pngquant()
+        .speed(1)
+        .ncolors(256)
+        .flush();
+
+      return expect(executeSpy.returnValues[0], 'to equal', [
+        '--speed',
+        1,
+        256,
+        '-'
+      ]).finally(() => {
+        executeSpy.restore();
+      });
+    });
   });
 
   describe('with the pngcrush engine', function() {
diff --git a/test/queryString.js b/test/queryString.js
index a3027dc..b4e8072 100644
--- a/test/queryString.js
+++ b/test/queryString.js
@@ -232,9 +232,9 @@ describe('queryString', function() {
 
     it('should parse pngquant with integer argument correctly', () => {
       localExpect(
-        'resize=800,800&pngquant=8',
+        'resize=800,800&pngquant=256',
         'when prepared to equal',
-        'resize=800,800&pngquant&speed=8'
+        'resize=800,800&pngquant&ncolors=256'
       );
     });
 

From b545091135d222d6cf81462dba866cc5d0c89184 Mon Sep 17 00:00:00 2001
From: Alex J Burke <alex@alexjeffburke.com>
Date: Thu, 21 May 2020 12:47:22 +0200
Subject: [PATCH 2/2] Catch up another test.

---
 test/queryString.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/queryString.js b/test/queryString.js
index b4e8072..b69b6a6 100644
--- a/test/queryString.js
+++ b/test/queryString.js
@@ -258,7 +258,7 @@ describe('queryString', function() {
       localExpect(
         'resize=800,800&pngquant=8&pngcrush=-rem,gAMA',
         'when prepared to equal',
-        'resize=800,800&pngquant&speed=8&pngcrush&rem=gAMA'
+        'resize=800,800&pngquant&ncolors=8&pngcrush&rem=gAMA'
       );
     });