Add new eslint rules (#2121)

The largest changes here are:
- enforcing single quotes for strings
- enforcing trailing commas where possible

In addition to those we have enabled several eslint plugins:
- plugin:requirejs/recommended, to enforce some conventions in require statements
- plugin:node/recommended, to enforce correct usage of various node.js APIs
- plugin:unicorn/recommended, which contains a pretty mixed bag of useful rules

This PR attempts to not change code behavior when possible.  In cases where fixing
existing code would change semantics, a linting exclusion has been placed in the 
code base to silence the error.  You can find these by searching for `eslint-disable-next-line`.

Co-authored-by: Austin Morton <austinpmorton@gmail.com>

1 files changed, 26 insertions, 26 deletions

diff --git a/lib/compilers/pascal.js b/lib/compilers/pascal.js
index 8f82fb824..424a6381f 100644
--- a/lib/compilers/pascal.js
+++ b/lib/compilers/pascal.js
@@ -21,14 +21,14 @@
 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
-"use strict";
+'use strict';
 
 const BaseCompiler = require('../base-compiler'),
     utils = require('../utils'),
     _ = require('underscore'),
-    fs = require("fs-extra"),
-    path = require("path"),
-    argumentParsers = require("./argument-parsers");
+    fs = require('fs-extra'),
+    path = require('path'),
+    argumentParsers = require('./argument-parsers');
 
 class FPCCompiler extends BaseCompiler {
     constructor(info, env) {
@@ -66,7 +66,7 @@ class FPCCompiler extends BaseCompiler {
         let options = ['-g', '-al'];
 
         if (this.compiler.intelAsm && filters.intel && !filters.binary) {
-            options = options.concat(this.compiler.intelAsm.split(" "));
+            options = options.concat(this.compiler.intelAsm.split(' '));
         }
 
         filters.preProcessLines = _.bind(this.preProcessLines, this);
@@ -79,20 +79,20 @@ class FPCCompiler extends BaseCompiler {
     }
 
     getExecutableFilename(dirPath) {
-        return path.join(dirPath, "prog");
+        return path.join(dirPath, 'prog');
     }
 
     static preProcessBinaryAsm(input) {
-        const relevantAsmStartsAt = input.indexOf("<OUTPUT");
+        const relevantAsmStartsAt = input.indexOf('<OUTPUT');
         if (relevantAsmStartsAt !== -1) {
-            const lastLinefeedBeforeStart = input.lastIndexOf("\n", relevantAsmStartsAt);
+            const lastLinefeedBeforeStart = input.lastIndexOf('\n', relevantAsmStartsAt);
             if (lastLinefeedBeforeStart !== -1) {
                 input =
-                    input.substr(0, input.indexOf("00000000004")) + "\n" +
+                    input.substr(0, input.indexOf('00000000004')) + '\n' +
                     input.substr(lastLinefeedBeforeStart + 1);
             } else {
                 input =
-                    input.substr(0, input.indexOf("00000000004")) + "\n" +
+                    input.substr(0, input.indexOf('00000000004')) + '\n' +
                     input.substr(relevantAsmStartsAt);
             }
         }
@@ -102,13 +102,13 @@ class FPCCompiler extends BaseCompiler {
     async objdump(outputFilename, result, maxSize, intelAsm, demangle) {
         const dirPath = path.dirname(outputFilename);
         outputFilename = this.getExecutableFilename(dirPath);
-        let args = ["-d", outputFilename, "-l", "--insn-width=16"];
-        if (demangle) args = args.concat(["-C"]);
-        if (intelAsm) args = args.concat(["-M", "intel"]);
+        let args = ['-d', outputFilename, '-l', '--insn-width=16'];
+        if (demangle) args = args.concat(['-C']);
+        if (intelAsm) args = args.concat(['-M', 'intel']);
         const objResult = await this.exec(
             this.compiler.objdumper, args, {maxOutput: maxSize, customCwd: dirPath});
         if (objResult.code !== 0) {
-            result.asm = "<No output: objdump returned " + objResult.code + ">";
+            result.asm = '<No output: objdump returned ' + objResult.code + '>';
         } else {
             result.asm = FPCCompiler.preProcessBinaryAsm(objResult.stdout);
         }
@@ -119,10 +119,10 @@ class FPCCompiler extends BaseCompiler {
         const unitName = path.basename(this.compileFilename, this.lang.extensions[0]);
 
         await fs.writeFile(filename,
-            "program prog; " +
-            "uses " + unitName + " in '" + this.compileFilename + "'; " +
-            "begin " +
-            "end.");
+            'program prog; ' +
+            'uses ' + unitName + " in '" + this.compileFilename + "'; " +
+            'begin ' +
+            'end.');
     }
 
     async runCompiler(compiler, options, inputFilename, execOptions) {
@@ -131,7 +131,7 @@ class FPCCompiler extends BaseCompiler {
         }
 
         const dirPath = path.dirname(inputFilename);
-        const projectFile = path.join(dirPath, "prog.dpr");
+        const projectFile = path.join(dirPath, 'prog.dpr');
         execOptions.customCwd = dirPath;
 
         await this.saveDummyProjectFile(projectFile);
@@ -163,23 +163,23 @@ class FPCCompiler extends BaseCompiler {
     }
 
     getExtraAsmHint(asm) {
-        if (asm.startsWith("# [")) {
-            const bracketEndPos = asm.indexOf("]", 3);
+        if (asm.startsWith('# [')) {
+            const bracketEndPos = asm.indexOf(']', 3);
             let valueInBrackets = asm.substr(3, bracketEndPos - 3);
-            const colonPos = valueInBrackets.indexOf(":");
+            const colonPos = valueInBrackets.indexOf(':');
             if (colonPos !== -1) {
                 valueInBrackets = valueInBrackets.substr(0, colonPos - 1);
             }
 
             if (!isNaN(valueInBrackets)) {
-                return "  .loc 1 " + valueInBrackets + " 0";
+                return '  .loc 1 ' + valueInBrackets + ' 0';
             } else if (valueInBrackets.includes(this.compileFilename)) {
-                return "  .file 1 \"<stdin>\"";
+                return '  .file 1 "<stdin>"';
             } else {
                 return false;
             }
-        } else if (asm.startsWith(".Le")) {
-            return "  .cfi_endproc";
+        } else if (asm.startsWith('.Le')) {
+            return '  .cfi_endproc';
         } else {
             return false;
         }