[max-line-length] ignore strings and regex in max line length (#4798)

* Added option to ignore max line lenght errors when caused by strings or template strings.

* Added tests for default state, when strings are ignored, and for string checks enabled.

* Fixed linter errors.

* Use different functions to detect if node is a string, because of tests with older versions.

* Using simple comparison to detect node kind.

* Fully switched to simple comparison instead of helper functions.

* Added option to check regular expressions if they exceed the maximum line length.

* Moved ignore check logic into it's own function.

* Renamed test folder name to express that strings and regex are checked.

* Refactored hardcoded option strings with constant variables that are used consistently.

* Changed max line length rule options interfacee back to camelcase and combined the two consecutive filter calls into one.

src/rules/maxLineLengthRule.ts

@@ -15,14 +15,21 @@
  * limitations under the License.
  */
 
-import { getLineRanges } from "tsutils";
+import { getLineRanges, getTokenAtPosition, LineRange } from "tsutils";
 import * as ts from "typescript";
 
 import * as Lint from "../index";
 
+const OPTION_LIMIT = "limit";
+const OPTION_IGNORE_PATTERN = "ignore-pattern";
+const OPTION_CHECK_STRINGS = "check-strings";
+const OPTION_CHECK_REGEX = "check-regex";
+
 interface MaxLineLengthRuleOptions {
     limit: number;
     ignorePattern?: RegExp;
+    checkStrings?: boolean;
+    checkRegex?: boolean;
 }
 
 export class Rule extends Lint.Rules.AbstractRule {
@@ -38,14 +45,16 @@ export class Rule extends Lint.Rules.AbstractRule {
         It can take one argument, which can be any of the following:
         * integer indicating maximum length of lines.
         * object with keys:
-          * \`limit\` - number greater than 0 defining the max line length
-          * \`ignore-pattern\` - string defining ignore pattern for this rule, being parsed by \`new RegExp()\`.
+          * \`${OPTION_LIMIT}\` - number greater than 0 defining the max line length
+          * \`${OPTION_IGNORE_PATTERN}\` - string defining ignore pattern for this rule, being parsed by \`new RegExp()\`.
             For example:
              * \`\/\/ \` pattern will ignore all in-line comments.
              * \`^import \` pattern will ignore all import statements.
              * \`^export \{(.*?)\}\` pattern will ignore all multiple export statements.
              * \`class [a-zA-Z]+ implements \` pattern will ignore all class declarations implementing interfaces.
              * \`^import |^export \{(.*?)\}|class [a-zA-Z]+ implements |// \` pattern will ignore all the cases listed above.
+          * \`${OPTION_CHECK_STRINGS}\` - determines if strings should be checked, \`false\` by default.
+          * \`${OPTION_CHECK_REGEX}\` - determines if regular expressions should be checked, \`false\` by default.
          `,
         options: {
             type: "array",
@@ -57,8 +66,10 @@ export class Rule extends Lint.Rules.AbstractRule {
                     {
                         type: "object",
                         properties: {
-                            limit: { type: "number" },
-                            "ignore-pattern": { type: "string" },
+                            [OPTION_LIMIT]: { type: "number" },
+                            [OPTION_IGNORE_PATTERN]: { type: "string" },
+                            [OPTION_CHECK_STRINGS]: { type: "boolean" },
+                            [OPTION_CHECK_REGEX]: { type: "boolean" },
                         },
                         additionalProperties: false,
                     },
@@ -72,8 +83,10 @@ export class Rule extends Lint.Rules.AbstractRule {
             [
                 true,
                 {
-                    limit: 120,
-                    "ignore-pattern": "^import |^export {(.*?)}",
+                    [OPTION_LIMIT]: 120,
+                    [OPTION_IGNORE_PATTERN]: "^import |^export {(.*?)}",
+                    [OPTION_CHECK_STRINGS]: true,
+                    [OPTION_CHECK_REGEX]: true,
                 },
             ],
         ],
@@ -87,7 +100,7 @@ export class Rule extends Lint.Rules.AbstractRule {
     }
 
     public isEnabled(): boolean {
-        const limit = this.getRuleOptions().limit;
+        const limit = this.getRuleOptions()[OPTION_LIMIT];
         return super.isEnabled() && limit > 0;
     }
 
@@ -96,32 +109,95 @@ export class Rule extends Lint.Rules.AbstractRule {
     }
 
     private getRuleOptions(): MaxLineLengthRuleOptions {
-        const argument = this.ruleArguments[0];
-        let options: MaxLineLengthRuleOptions = { limit: 0 };
+        const argument = this.ruleArguments[0] as { [key: string]: any } | number;
+
         if (typeof argument === "number") {
-            options.limit = argument;
+            return { limit: argument };
         } else {
-            options = argument as MaxLineLengthRuleOptions;
-            const ignorePattern = (argument as { [key: string]: string })["ignore-pattern"];
-            options.ignorePattern =
-                typeof ignorePattern === "string" ? new RegExp(ignorePattern) : undefined;
+            const {
+                [OPTION_CHECK_REGEX]: checkRegex,
+                [OPTION_CHECK_STRINGS]: checkStrings,
+                [OPTION_IGNORE_PATTERN]: ignorePattern,
+                [OPTION_LIMIT]: limit,
+            } = argument;
+
+            return {
+                checkRegex: Boolean(checkRegex),
+                checkStrings: Boolean(checkStrings),
+                ignorePattern:
+                    typeof ignorePattern === "string" ? new RegExp(ignorePattern) : undefined,
+                limit: Number(limit),
+            };
         }
-        options.limit = Number(options.limit); // user can pass a string instead of number
-        return options;
     }
 }
 
 function walk(ctx: Lint.WalkContext<MaxLineLengthRuleOptions>) {
-    const limit = ctx.options.limit;
-    const ignorePattern = ctx.options.ignorePattern;
-    for (const line of getLineRanges(ctx.sourceFile)) {
-        if (line.contentLength <= limit) {
-            continue;
+    const { limit } = ctx.options;
+
+    getLineRanges(ctx.sourceFile)
+        .filter(
+            (line: LineRange): boolean =>
+                line.contentLength > limit && !shouldIgnoreLine(line, ctx),
+        )
+        .forEach(({ pos, contentLength }: LineRange) =>
+            ctx.addFailureAt(pos, contentLength, Rule.FAILURE_STRING_FACTORY(limit)),
+        );
+
+    return;
+}
+
+function shouldIgnoreLine(
+    { pos, contentLength }: LineRange,
+    { options, sourceFile }: Lint.WalkContext<MaxLineLengthRuleOptions>,
+): boolean {
+    const { checkRegex, checkStrings, ignorePattern, limit } = options;
+
+    let shouldOmitLine = false;
+
+    if (ignorePattern !== undefined) {
+        shouldOmitLine =
+            shouldOmitLine || ignorePattern.test(sourceFile.text.substr(pos, contentLength));
+    }
+
+    if (!checkStrings) {
+        const nodeAtLimit: ts.Node | undefined = getTokenAtPosition(sourceFile, pos + limit);
+
+        if (nodeAtLimit !== undefined) {
+            shouldOmitLine =
+                shouldOmitLine ||
+                nodeAtLimit.kind === ts.SyntaxKind.StringLiteral ||
+                nodeAtLimit.kind === ts.SyntaxKind.NoSubstitutionTemplateLiteral ||
+                hasParentMatchingTypes(nodeAtLimit, sourceFile, [ts.SyntaxKind.TemplateExpression]);
         }
-        const lineContent = ctx.sourceFile.text.substr(line.pos, line.contentLength);
-        if (ignorePattern !== undefined && ignorePattern.test(lineContent)) {
-            continue;
+    }
+
+    if (!checkRegex) {
+        const nodeAtLimit: ts.Node | undefined = getTokenAtPosition(sourceFile, pos + limit);
+
+        if (nodeAtLimit !== undefined) {
+            shouldOmitLine =
+                shouldOmitLine || nodeAtLimit.kind === ts.SyntaxKind.RegularExpressionLiteral;
         }
-        ctx.addFailureAt(line.pos, line.contentLength, Rule.FAILURE_STRING_FACTORY(limit));
     }
+
+    return shouldOmitLine;
+}
+
+function hasParentMatchingTypes(
+    node: ts.Node,
+    root: ts.Node,
+    parentTypes: ts.SyntaxKind[],
+): boolean {
+    let nodeReference: ts.Node = node;
+
+    while (nodeReference !== root) {
+        if (parentTypes.indexOf(nodeReference.kind) >= 0) {
+            return true;
+        }
+
+        nodeReference = nodeReference.parent;
+    }
+
+    return false;
 }

test/rules/max-line-length/check-strings-and-regex/test.ts.lint

@@ -0,0 +1,33 @@
+import { KindOfOneVerySpecificComponentOrSomethingLikeThis } from '../../../../very/very/very/very/very/long/and/complicated/and/nested/directory/structure/target';
+
+var simpleName = 1;
+var complicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedName;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+var complicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicat;
+
+const extremelyLongSingleQuoteString = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu';
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+const extremelyLongDoubleQuoteString = "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu";
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+const extremelyLongTemplateString = `Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu`;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+const extremelyLongTemplateStringWithVariableAtLimit = `Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod ${simpleName} ut labore et dolore magna aliquyam `;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+const multiLineTemplateString = `
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+`;
+
+const veryLongRegularExpression = /\s*********************************************************************************************************************/;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+[0]: Exceeds maximum line length of 140

test/rules/max-line-length/check-strings-and-regex/tslint.json

@@ -0,0 +1,10 @@
+{
+  "rules": {
+    "max-line-length": [true, {
+      "limit": "140",
+      "ignore-pattern": "^import ",
+      "check-strings": true,
+      "check-regex": true
+    }]
+  }
+}

test/rules/max-line-length/default/test.ts.lint

@@ -0,0 +1,25 @@
+import { KindOfOneVerySpecificComponentOrSomethingLikeThis } from '../../../../very/very/very/very/very/long/and/complicated/and/nested/directory/structure/target';
+
+var simpleName = 1;
+var complicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedName;
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [0]
+
+var complicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicatedNameIsAcomplicat;
+
+const extremelyLongSingleQuoteString = 'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu';
+
+const extremelyLongDoubleQuoteString = "Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu";
+
+const extremelyLongTemplateString = `Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu`;
+
+const extremelyLongTemplateStringWithVariableAtLimit = `Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod ${someVariable} ut labore et dolore magna aliquyam `;
+
+const multiLineTemplateString = `
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam volu
+`;
+
+const veryLongRegularExpression = /\s*********************************************************************************************************************/;
+
+[0]: Exceeds maximum line length of 140

test/rules/max-line-length/tslint.json → test/rules/max-line-length/default/tslint.json

@@ -1,8 +1,7 @@
 {
   "rules": {
     "max-line-length": [true, {
-      "limit": 140,
-      "ignore-pattern": "^import "
+      "limit": 140
     }]
   }
 }