Fix input prompt repeating value when value is longer than terminal width. Closes #214

lib/prompts/base.js

@@ -8,7 +8,6 @@ var _ = require("lodash");
 var chalk = require("chalk");
 var ansiRegex = require("ansi-regex");
 var readline = require("readline");
-var cliWidth = require("cli-width");
 var utils = require("../utils/utils");
 var Choices = require("../objects/choices");
 var tty = require("../utils/tty");
@@ -96,7 +95,7 @@ Prompt.prototype.throwParamError = function( name ) {
  */
 
 Prompt.prototype.error = function( error ) {
-  readline.moveCursor( this.rl.output, -cliWidth(), 0 );
+  readline.moveCursor( this.rl.output, -utils.cliWidth(), 0 );
   readline.clearLine( this.rl.output, 0 );
 
   var errMsg = chalk.red(">> ") +
@@ -114,7 +113,7 @@ Prompt.prototype.error = function( error ) {
  */
 
 Prompt.prototype.hint = function( hint ) {
-  readline.moveCursor( this.rl.output, -cliWidth(), 0 );
+  readline.moveCursor( this.rl.output, -utils.cliWidth(), 0 );
   readline.clearLine( this.rl.output, 0 );
 
   if ( hint.length ) {

lib/prompts/input.js

@@ -2,6 +2,7 @@
  * `input` type prompt
  */
 
+var os = require("os");
 var _ = require("lodash");
 var util = require("util");
 var chalk = require("chalk");
@@ -82,7 +83,7 @@ Prompt.prototype.onEnd = function( state ) {
     this.status = "answered";
 
     // Re-render prompt
-    this.clean(1).render();
+    this.clean( this.lines() ).render();
 
     // Render answer
     this.write( chalk.cyan(filteredValue) + "\n" );
@@ -100,5 +101,14 @@ Prompt.prototype.onError = function( state ) {
  */
 
 Prompt.prototype.onKeypress = function() {
-  this.clean().render().write( this.rl.line );
-};
+  var lines = this.lines();
+
+  // Windows duplicates the line only when the
+  // first character wraps to another line
+  if ( os.platform() === "win32" && this.previousLines === lines + 1 ) {
+    this.clean( 1 ).render();
+  }
+
+  this.previousLines = lines;
+  this.clean( this.previousLines - 1 ).render().write( this.rl.line );
+};

lib/utils/tty.js

@@ -2,12 +2,55 @@
  * TTY mixin helpers
  */
 
+var os = require("os");
 var _ = require("lodash");
 var readline = require("readline");
-var cliWidth = require("cli-width");
+var unicodeLength = require("unicode-length");
+var utils = require("./utils");
 
 var tty = module.exports;
 
+/**
+ * Get the number of lines the current line occupies
+ * @return {Number}  The number of lines
+ */
+
+tty.lines = function() {
+  var terminalWidth = utils.cliWidth();
+
+  if ( terminalWidth === 0 ) {
+
+    // Preserve original behaviour
+    return 1;
+  }
+
+  var value = this.rl.line;
+
+  if ( !value ) {
+    if ( this.rl.history ) {
+      value = this.rl.history[0];
+    } else {
+      value = this.opt.default;
+    }
+  }
+
+  var lineLength = unicodeLength.get( this.rl._prompt + value );
+
+  // Windows seems to wraps the line one character
+  // before the window width for some reason
+  if ( os.platform() === "win32" ) {
+    lineLength += 1;
+  }
+
+  var result = lineLength / terminalWidth;
+
+  if ( result % 1 === 0 ) {
+    return result;
+  } else {
+    return Math.floor( result ) + 1;
+  }
+};
+
 
 /**
  * Remove the prompt from screen
@@ -21,7 +64,7 @@ tty.clean = function( extra ) {
   var len = this.height + extra;
 
   while ( len-- ) {
-    readline.moveCursor(this.rl.output, -cliWidth(), 0);
+    readline.moveCursor(this.rl.output, -utils.cliWidth(), 0);
     readline.clearLine(this.rl.output, 0);
     if ( len ) readline.moveCursor(this.rl.output, 0, -1);
   }

lib/utils/utils.js

@@ -7,6 +7,7 @@ var _ = require("lodash");
 var chalk = require("chalk");
 var rx = require("rx");
 var figures = require("figures");
+var cliWidth = require("cli-width");
 
 
 /**
@@ -121,3 +122,14 @@ utils.writeMessage = function ( prompt, message ) {
   }
   prompt.write( message );
 };
+
+
+/**
+ * Helper for getting the terminal width
+ * Wraps cli-width for stub purposes
+ * @return {Number} - The terminal width
+ */
+
+utils.cliWidth = function() {
+  return cliWidth();
+};

package.json

@@ -28,7 +28,8 @@
     "lodash": "^3.3.1",
     "readline2": "^0.1.1",
     "rx": "^2.4.3",
-    "through": "^2.3.6"
+    "through": "^2.3.6",
+    "unicode-length": "^1.0.0"
   },
   "devDependencies": {
     "chai": "^2.1.2",

test/helpers/readline.js

@@ -11,6 +11,7 @@ var stub = {
   pause         : sinon.stub().returns(stub),
   resume        : sinon.stub().returns(stub),
   _getCursorPos : sinon.stub().returns(stub),
+  _prompt       : sinon.stub().returns(stub),
   output        : {
     end    : sinon.stub().returns(stub),
     mute   : sinon.stub().returns(stub),

test/specs/prompts/input.js

@@ -4,6 +4,7 @@ var _ = require("lodash");
 var ReadlineStub = require("../../helpers/readline");
 var fixtures = require("../../helpers/fixtures");
 
+var utils = require("../../../lib/utils/utils");
 var Input = require("../../../lib/prompts/input");
 
 
@@ -53,4 +54,71 @@ describe("`input` prompt", function() {
     this.rl.emit("line", "");
   });
 
+  describe("given a terminal width", function() {
+
+    beforeEach(function() {
+      this.cliWidthStub = sinon.stub( utils, "cliWidth" );
+      this.cliWidthStub.returns(20);
+    });
+
+    afterEach(function() {
+      this.cliWidthStub.restore();
+    });
+
+    it("should clean short lines appropriately", function( done ) {
+      var prompt = new Input( this.fixture, this.rl );
+      var cleanSpy = sinon.spy( prompt, "clean" );
+      prompt.run(function() {
+        expect( cleanSpy.callCount ).to.equal(1);
+        expect( cleanSpy.calledWith(1) ).to.be.true;
+        done();
+      }.bind(this));
+
+      this.rl.line = "hello";
+      this.rl.emit( "line", this.rl.line );
+    });
+
+    it("should clean wrapped long lines", function( done ) {
+      var prompt = new Input( this.fixture, this.rl );
+      var cleanSpy = sinon.spy( prompt, "clean" );
+      prompt.run(function() {
+        expect( cleanSpy.callCount ).to.equal(1);
+        expect( cleanSpy.calledWith(3) ).to.be.true;
+        done();
+      }.bind(this));
+
+      this.rl.line = "asdfasdfasdfasdfasdfasdfasdfasdfasdfasdf";
+      this.rl.emit( "line", this.rl.line );
+    });
+
+  });
+
+  describe("given no terminal width", function() {
+
+    beforeEach(function() {
+      this.cliWidthStub = sinon.stub( utils, "cliWidth" );
+
+      // Return the default value
+      this.cliWidthStub.returns(0);
+    });
+
+    afterEach(function() {
+      this.cliWidthStub.restore();
+    });
+
+    it("should clean one line even if the input line is long", function( done ) {
+      var prompt = new Input( this.fixture, this.rl );
+      var cleanSpy = sinon.spy( prompt, "clean" );
+      prompt.run(function() {
+        expect( cleanSpy.callCount ).to.equal(1);
+        expect( cleanSpy.calledWith(1) ).to.be.true;
+        done();
+      }.bind(this));
+
+      this.rl.line = "asdfasdfasdfasdfasdfasdfasdfasdfasdfasdf";
+      this.rl.emit( "line", this.rl.line );
+    });
+
+  });
+
 });