Lint tweaks (#422)

* switch to always using a space in object curly braces
* consistently use strict mode
* move a constant outside of the constructor
* use Object spread instead of Object.assign
* use a ternary in more places
* remove redundant parentheses
* enable `prefer-template` rule so that we are consistent
* return early in a few cases

5 files changed, 98 insertions, 88 deletions

diff --git a/examples/scss/gulpfile.js b/examples/scss/gulpfile.js
index 4232d3f..b9d0ecb 100644
--- a/examples/scss/gulpfile.js
+++ b/examples/scss/gulpfile.js
@@ -5,7 +5,7 @@ const sass = require('gulp-sass')(require('sass'));
 
 gulp.task('default', () => {
   return gulp.src('./src/**/*.scss')
-    .pipe(sass({outputStyle: 'expanded'}).on('error', sass.logError))
+    .pipe(sass({ outputStyle: 'expanded' }).on('error', sass.logError))
     .pipe(gulp.dest('./dest'));
 });
 
diff --git a/lib/rfs.js b/lib/rfs.js
index 850c93f..4f0ec03 100644
--- a/lib/rfs.js
+++ b/lib/rfs.js
@@ -1,3 +1,5 @@
+'use strict';
+
 const postcss = require('postcss');
 const valueParser = require('postcss-value-parser');
 
@@ -5,23 +7,23 @@ const BREAKPOINT_ERROR = 'breakpoint option is invalid, it should be set in `px`
 const BREAKPOINT_UNIT_ERROR = 'breakpointUnit option is invalid, it should be `px`, `rem` or `em`.';
 const BASE_RFS_ERROR = 'baseValue option is invalid, it should be set in `px` or `rem`.';
 
+const defaultOptions = {
+  baseValue: 20,
+  unit: 'rem',
+  breakpoint: 1200,
+  breakpointUnit: 'px',
+  factor: 10,
+  twoDimensional: false,
+  unitPrecision: 5,
+  remValue: 16,
+  functionName: 'rfs',
+  enableRfs: true,
+  mode: 'min-media-query'
+};
+
 module.exports = class {
   constructor(opts) {
-    const defaultOptions = {
-      baseValue: 20,
-      unit: 'rem',
-      breakpoint: 1200,
-      breakpointUnit: 'px',
-      factor: 10,
-      twoDimensional: false,
-      unitPrecision: 5,
-      remValue: 16,
-      functionName: 'rfs',
-      enableRfs: true,
-      mode: 'min-media-query'
-    };
-
-    this.opts = Object.assign(defaultOptions, opts);
+    this.opts = { ...defaultOptions, ...opts };
 
     if (typeof this.opts.baseValue !== 'number') {
       if (this.opts.baseValue.endsWith('px')) {
@@ -62,11 +64,9 @@ module.exports = class {
     }
 
     // Render value in desired unit
-    if (this.opts.unit === 'rem') {
-      return `${this.toFixed(value / this.opts.remValue, this.opts.unitPrecision)}rem`;
-    }
-
-    return `${this.toFixed(value, this.opts.unitPrecision)}px`;
+    return this.opts.unit === 'rem' ?
+      `${this.toFixed(value / this.opts.remValue, this.opts.unitPrecision)}rem` :
+      `${this.toFixed(value, this.opts.unitPrecision)}px`;
   }
 
   process(declarationValue, fluid) {
@@ -112,11 +112,10 @@ module.exports = class {
           }
 
           const viewportUnit = this.opts.twoDimensional ? 'vmin' : 'vw';
-          if (value > 0) {
-            return `calc(${this.toFixed(baseValue, this.opts.unitPrecision)}${this.opts.unit} + ${this.toFixed(diff * 100 / this.opts.breakpoint, this.opts.unitPrecision)}${viewportUnit})`;
-          }
 
-          return `calc(-${this.toFixed(baseValue, this.opts.unitPrecision)}${this.opts.unit} - ${this.toFixed(diff * 100 / this.opts.breakpoint, this.opts.unitPrecision)}${viewportUnit})`;
+          return value > 0 ?
+            `calc(${this.toFixed(baseValue, this.opts.unitPrecision)}${this.opts.unit} + ${this.toFixed(diff * 100 / this.opts.breakpoint, this.opts.unitPrecision)}${viewportUnit})` :
+            `calc(-${this.toFixed(baseValue, this.opts.unitPrecision)}${this.opts.unit} - ${this.toFixed(diff * 100 / this.opts.breakpoint, this.opts.unitPrecision)}${viewportUnit})`;
         });
       }
 
@@ -146,9 +145,9 @@ module.exports = class {
       name: 'media'
     };
 
-    const dimPrefix = (this.opts.mode === 'min-media-query') ? 'min' : 'max';
-    const dimConnector = (this.opts.mode === 'min-media-query') ? ' and' : ',';
-    const breakpoint = (this.opts.breakpointUnit === 'px') ? this.opts.breakpoint : this.opts.breakpoint / this.opts.remValue;
+    const dimPrefix = this.opts.mode === 'min-media-query' ? 'min' : 'max';
+    const dimConnector = this.opts.mode === 'min-media-query' ? ' and' : ',';
+    const breakpoint = this.opts.breakpointUnit === 'px' ? this.opts.breakpoint : this.opts.breakpoint / this.opts.remValue;
 
     mediaQuery.params = this.opts.twoDimensional ?
       `(${dimPrefix}-width: ${breakpoint}${this.opts.breakpointUnit})${dimConnector} (${dimPrefix}-height: ${breakpoint}${this.opts.breakpointUnit})` :
@@ -161,4 +160,3 @@ module.exports = class {
     return this.opts;
   }
 };
-
diff --git a/package.json b/package.json
index 600c1bd..4b84ea8 100644
--- a/package.json
+++ b/package.json
@@ -95,10 +95,15 @@
         "never"
       ],
       "node/prefer-promises/fs": "off",
+      "object-curly-spacing": [
+        "error",
+        "always"
+      ],
       "operator-linebreak": [
         "error",
         "after"
       ],
+      "prefer-template": "error",
       "promise/prefer-await-to-then": "off",
       "unicorn/prefer-module": "off",
       "unicorn/prevent-abbreviations": "off"
diff --git a/postcss.js b/postcss.js
index 9f44ea8..9e45a5e 100644
--- a/postcss.js
+++ b/postcss.js
@@ -25,7 +25,7 @@ module.exports = postcss.plugin('postcss-rfs', opts => {
     css.walkRules(rule => {
       const mediaQueryRules = [];
       const extraBlocks = [];
-      const {parent} = rule;
+      const { parent } = rule;
       let removeRule = false;
       let dcRule;
       let ecRule;
@@ -54,7 +54,7 @@ module.exports = postcss.plugin('postcss-rfs', opts => {
         let ruleSelector = '';
 
         for (const selector of selectors) {
-          ruleSelector += (opts.mode === 'max-media-query') ? `${selector},\n` : '';
+          ruleSelector += opts.mode === 'max-media-query' ? `${selector},\n` : '';
           ruleSelector += `${DISABLE_RFS_SELECTOR} ${selector},\n`;
           ruleSelector += `${selector + DISABLE_RFS_SELECTOR},\n`;
         }
@@ -69,76 +69,83 @@ module.exports = postcss.plugin('postcss-rfs', opts => {
 
       rule.walkDecls(decl => {
         // Check if the selector doesn't contain the disabled selector
-        // Check if value contains rfs() function
-        if (!rule.selector.includes(DISABLE_RFS_SELECTOR) && new RegExp(opts.functionName + '(.*)', 'g').test(decl.value)) {
-          const value = rfs.value(decl.value);
-          const fluidValue = rfs.fluidValue(decl.value);
-          decl.value = value;
-
-          if (value !== fluidValue) {
-            const defaultValue = (opts.mode === 'min-media-query') ? ((opts.class === 'enable') ? value : fluidValue) : value;
-            const mediaQueryValue = (opts.mode === 'min-media-query') ? value : fluidValue;
-            decl.value = defaultValue;
-
-            fluidRule.append(decl.clone({value: mediaQueryValue}));
-            mediaQueryRules.push(fluidRule);
-
-            // Disable classes
-            if (opts.class === 'disable') {
-              const declOpts = (opts.mode === 'max-media-query') ? {} : {value};
-              dcRule.append(decl.clone(declOpts));
-              extraBlocks.push(dcRule);
-            } else if (opts.class === 'enable' && opts.mode === 'min-media-query') {
-              if (ecRule === undefined) {
-                ecRule = postcss.rule({
-                  selector: ruleSelector,
-                  source: parent.source
-                });
-              }
-
-              ecRule.append(decl.clone({value: fluidValue}));
-              extraBlocks.push(ecRule);
+        // and if the value contains the rfs() function
+        const check = !rule.selector.includes(DISABLE_RFS_SELECTOR) &&
+          new RegExp(`${opts.functionName}(.*)`, 'g').test(decl.value);
+
+        if (!check) {
+          return;
+        }
+
+        const value = rfs.value(decl.value);
+        const fluidValue = rfs.fluidValue(decl.value);
+        decl.value = value;
+
+        if (value !== fluidValue) {
+          const defaultValue = opts.mode === 'min-media-query' ? ((opts.class === 'enable') ? value : fluidValue) : value;
+          const mediaQueryValue = opts.mode === 'min-media-query' ? value : fluidValue;
+          decl.value = defaultValue;
+
+          fluidRule.append(decl.clone({ value: mediaQueryValue }));
+          mediaQueryRules.push(fluidRule);
+
+          // Disable classes
+          if (opts.class === 'disable') {
+            const declOpts = opts.mode === 'max-media-query' ? {} : { value };
+            dcRule.append(decl.clone(declOpts));
+            extraBlocks.push(dcRule);
+          } else if (opts.class === 'enable' && opts.mode === 'min-media-query') {
+            if (ecRule === undefined) {
+              ecRule = postcss.rule({
+                selector: ruleSelector,
+                source: parent.source
+              });
             }
 
-            // Remove declaration if needed
-            if (opts.class === 'disable' && opts.mode === 'max-media-query') {
-              if (decl.prev() || decl.next()) {
-                decl.remove();
-              } else {
-                removeRule = true;
-              }
+            ecRule.append(decl.clone({ value: fluidValue }));
+            extraBlocks.push(ecRule);
+          }
+
+          // Remove declaration if needed
+          if (opts.class === 'disable' && opts.mode === 'max-media-query') {
+            if (decl.prev() || decl.next()) {
+              decl.remove();
+            } else {
+              removeRule = true;
             }
           }
         }
       });
 
-      if (mediaQueryRules.length > 0) {
-        // Safari iframe resize bug: https://github.com/twbs/rfs/issues/14
-        if (opts.safariIframeResizeBugFix) {
-          rule.append({
-            prop: 'min-width',
-            value: '0vw'
-          });
-        }
+      if (mediaQueryRules.length === 0) {
+        return;
+      }
 
-        const fluidMediaQuery = mediaQuery.clone();
+      // Safari iframe resize bug: https://github.com/twbs/rfs/issues/14
+      if (opts.safariIframeResizeBugFix) {
+        rule.append({
+          prop: 'min-width',
+          value: '0vw'
+        });
+      }
 
-        for (const mediaQueryRule of mediaQueryRules) {
-          fluidMediaQuery.append(mediaQueryRule);
-        }
+      const fluidMediaQuery = mediaQuery.clone();
 
-        parent.insertAfter(rule, fluidMediaQuery);
+      for (const mediaQueryRule of mediaQueryRules) {
+        fluidMediaQuery.append(mediaQueryRule);
+      }
 
-        if (extraBlocks.length > 0) {
-          for (const disableBlock of extraBlocks) {
-            parent.insertAfter(rule, disableBlock);
-          }
-        }
+      parent.insertAfter(rule, fluidMediaQuery);
 
-        if (removeRule) {
-          rule.remove();
+      if (extraBlocks.length > 0) {
+        for (const disableBlock of extraBlocks) {
+          parent.insertAfter(rule, disableBlock);
         }
       }
+
+      if (removeRule) {
+        rule.remove();
+      }
     });
   };
 });
diff --git a/test/lib/result.js b/test/lib/result.js
index cd41b45..0dea480 100644
--- a/test/lib/result.js
+++ b/test/lib/result.js
@@ -17,7 +17,7 @@ const postcssTests = require('../postcss/tests.js');
 
 // Functions
 function format(css) {
-  return prettier.format(css, {parser: 'css'}).replace(/(\n)(\n)/g, '$1');
+  return prettier.format(css, { parser: 'css' }).replace(/(\n)(\n)/g, '$1');
 }
 
 function getFileContent(folder, id, ext) {