Ignore missing / unavailable files

.eslintrc

@@ -1,12 +1,15 @@
 {
     "rules": {
+        "array-bracket-spacing": [ "error", "always" ],
         "indent": [ 2, "tab", { "SwitchCase": 1 } ],
         "quotes": [ 2, "single" ],
         "linebreak-style": [ 2, "unix" ],
         "semi": [ 2, "always" ],
         "keyword-spacing": [ 2, { "before": true, "after": true } ],
         "space-before-blocks": [ 2, "always" ],
+        "space-in-parens": [ "error", "always", { "exceptions": [ "{}", "[]" ] } ],
         "space-before-function-paren": [ 2, "always" ],
+        "object-curly-spacing": [ "error", "always" ],
         "no-mixed-spaces-and-tabs": [ 2, "smart-tabs" ],
         "no-cond-assign": [ 0 ]
     },

package.json

@@ -41,7 +41,7 @@
     "prepare-tests": "node test/samples/prepare-tests.js",
     "test": "mocha --compilers js:buble/register",
     "prepublish": "npm test",
-    "lint": "eslint src",
+    "lint": "eslint src --fix",
     "pretest-coverage": "npm run build",
     "test-coverage": "rm -rf coverage/* && istanbul cover --report json node_modules/.bin/_mocha -- -u exports -R spec test/test.js",
     "posttest-coverage": "remap-istanbul -i coverage/coverage-final.json -o coverage/coverage-remapped.json -b dist && remap-istanbul -i coverage/coverage-final.json -o coverage/coverage-remapped.lcov -t lcovonly -b dist && remap-istanbul -i coverage/coverage-final.json -o coverage/coverage-remapped -t html -b dist",
@@ -53,4 +53,4 @@
     "bin/",
     "README.md"
   ]
-}
+}

src/Chain.js

@@ -30,7 +30,7 @@ Chain.prototype = {
 		};
 	},
 
-	apply ( options = {} ) {
+	apply ( options = {}) {
 		let allNames = [];
 		let allSources = [];
 

src/Node.js

@@ -29,7 +29,7 @@ export default function Node ({ file, content }) {
 Node.prototype = {
 	load ( sourcesContentByPath, sourceMapByPath ) {
 		return getContent( this, sourcesContentByPath ).then( content => {
-			this.content = sourcesContentByPath[ this.file ] = content;
+			this.content = sourcesContentByPath[this.file] = content;
 
 			return getMap( this, sourceMapByPath ).then( map => {
 				if ( !map ) return null;
@@ -60,11 +60,15 @@ Node.prototype = {
 
 	loadSync ( sourcesContentByPath, sourceMapByPath ) {
 		if ( !this.content ) {
-			if ( !sourcesContentByPath[ this.file ] ) {
-				sourcesContentByPath[ this.file ] = readFileSync( this.file, { encoding: 'utf-8' });
+			if ( !sourcesContentByPath[this.file]) {
+				try {
+					sourcesContentByPath[this.file] = readFileSync( this.file, { encoding: 'utf-8' });
+				} catch ( e ) {
+					sourcesContentByPath[this.file] = null;
+				}
 			}
 
-			this.content = sourcesContentByPath[ this.file ];
+			this.content = sourcesContentByPath[this.file];
 		}
 
 		const map = getMap( this, sourceMapByPath, true );
@@ -121,7 +125,7 @@ Node.prototype = {
 
 		// Otherwise, we need to figure out what this position in
 		// the intermediate file corresponds to in *its* source
-		const segments = this.mappings[ lineIndex ];
+		const segments = this.mappings[lineIndex];
 
 		if ( !segments || segments.length === 0 ) {
 			return null;
@@ -146,8 +150,8 @@ Node.prototype = {
 					let sourceCodeColumn = segments[i][3];
 					let nameIndex = segments[i][4];
 
-					let parent = this.sources[ sourceFileIndex ];
-					return parent.trace( sourceCodeLine, sourceCodeColumn, this.map.names[ nameIndex ] || name );
+					let parent = this.sources[sourceFileIndex];
+					return parent.trace( sourceCodeLine, sourceCodeColumn, this.map.names[nameIndex] || name );
 				}
 			}
 		}
@@ -157,18 +161,18 @@ Node.prototype = {
 		let sourceCodeLine = segments[0][2];
 		let nameIndex = segments[0][4];
 
-		let parent = this.sources[ sourceFileIndex ];
-		return parent.trace( sourceCodeLine, null, this.map.names[ nameIndex ] || name );
+		let parent = this.sources[sourceFileIndex];
+		return parent.trace( sourceCodeLine, null, this.map.names[nameIndex] || name );
 	}
 };
 
 function getContent ( node, sourcesContentByPath ) {
 	if ( node.file in sourcesContentByPath ) {
-		node.content = sourcesContentByPath[ node.file ];
+		node.content = sourcesContentByPath[node.file];
 	}
 
 	if ( !node.content ) {
-		return readFile( node.file, { encoding: 'utf-8' });
+		return readFile( node.file, { encoding: 'utf-8' }).catch( () => null );
 	}
 
 	return Promise.resolve( node.content );

src/index.js

@@ -9,14 +9,14 @@ export function load ( file, options ) {
 		.then( () => node.isOriginalSource ? null : new Chain( node, sourcesContentByPath ) );
 }
 
-export function loadSync ( file, options = {} ) {
+export function loadSync ( file, options = {}) {
 	const { node, sourcesContentByPath, sourceMapByPath } = init( file, options );
 
 	node.loadSync( sourcesContentByPath, sourceMapByPath );
 	return node.isOriginalSource ? null : new Chain( node, sourcesContentByPath );
 }
 
-function init ( file, options = {} ) {
+function init ( file, options = {}) {
 	const node = new Node({ file });
 
 	let sourcesContentByPath = {};

src/utils/getMapFromUrl.js

@@ -37,8 +37,12 @@ export default function getMapFromUrl ( url, base, sync ) {
 	url = resolve( dirname( base ), decodeURI( url ) );
 
 	if ( sync ) {
-		return parseJSON( readFileSync( url, { encoding: 'utf-8' }), url );
+		try {
+			return parseJSON( readFileSync( url, { encoding: 'utf-8' }), url );
+		} catch ( e ) {
+			return null;
+		}
 	} else {
-		return readFile( url, { encoding: 'utf-8' }).then( json => parseJSON( json, url ) );
+		return readFile( url, { encoding: 'utf-8' }).then( json => parseJSON( json, url ) ).catch( () => null );
 	}
 }

src/utils/getSourceMappingUrl.js

@@ -1,6 +1,7 @@
 import SOURCEMAPPING_URL from './sourceMappingURL.js';
 
 export default function getSourceMappingUrl ( str ) {
+	if ( !str ) return null;
 	var index, substring, url, match;
 
 	// assume we want the last occurence