Solved: vscode [tslint] ' should be " (quotemark)

To solve “[tslint] ‘ should be ” (quotemark)” when developing spfx webpart using visual studio code, do these:

  1. open config/tslint.json
  2. add
{
    “$schema”: “https://dev.office.com/json-schemas/core-build/tslint.schema.json”,
    // Display errors as warnings
    “displayAsWarning”: false,
    // The TSLint task may have been configured with several custom lint rules
    // before this config file is read (for example lint rules from the tslint-microsoft-contrib
    // project). If true, this flag will deactivate any of these rules.
    “removeExistingRules”: true,
    // When true, the TSLint task is configured with some default TSLint “rules.”:
    “useDefaultConfigAsBase”: false,
    // Since removeExistingRules=true and useDefaultConfigAsBase=false, there will be no lint rules
    // which are active, other than the list of rules below.
    “lintConfig”: {
        // Opt-in to Lint rules which help to eliminate bugs in JavaScript
        “rules”: {
            “class-name”: false,
            “export-name”: false,
            “forin”: false,
            “label-position”: false,
            “member-access”: true,
            “no-arg”: false,
            “no-console”: false,
            “no-construct”: false,
            “no-duplicate-case”: true,
            “no-duplicate-variable”: true,
            “no-eval”: false,
            “no-function-expression”: true,
            “no-internal-module”: true,
            “no-shadowed-variable”: true,
            “no-switch-case-fall-through”: true,
            “no-unnecessary-semicolons”: true,
            “no-unused-expression”: true,
            “no-use-before-declare”: true,
            “no-with-statement”: true,
            “semicolon”: true,
            “trailing-comma”: false,
            “typedef”: false,
            “typedef-whitespace”: false,
            “use-named-parameter”: true,
            “valid-typeof”: true,
            “variable-name”: false,
            “whitespace”: false,
            “quotemark”: [“single”, “jsx-single”]
        }
    }
}
3. Test the result by “gulp build”