feat: add compile-time checking for selectors that don't exist when using index signature syntax, ie. a['my-selector'] (seek-oss#20)

Author: silbinarywolf

index.js

@@ -27,7 +27,7 @@ const cssModuleToInterface = (cssModuleKeys) => {
     .map(key => `  '${key}': string;`)
     .join('\n');
 
-  return `interface CssExports {\n${interfaceFields}\n}`;
+  return `interface CssExports {\n  [key: string]: void;\n${interfaceFields}\n}`;
 };
 
 const filenameToTypingsFilename = filename => {

test/emit-declaration/__snapshots__/emit-declaration.test.js.snap

@@ -4,6 +4,7 @@ exports[`Can emit valid declaration with sourceMap 1`] = `
 "// This file is automatically generated.
 // Please do not change this file!
 interface CssExports {
+  [key: string]: void;
   'composedClass': string;
   'otherClass': string;
   'someClass': string;
@@ -18,6 +19,7 @@ exports[`Can emit valid declaration without sourceMaps 1`] = `
 "// This file is automatically generated.
 // Please do not change this file!
 interface CssExports {
+  [key: string]: void;
   'composedClass': string;
   'otherClass': string;
   'someClass': string;

test/emit-empty-declaration/__snapshots__/emit-empty-declaration.test.js.snap

@@ -4,6 +4,7 @@ exports[`Can emit valid declaration without classes 1`] = `
 "// This file is automatically generated.
 // Please do not change this file!
 interface CssExports {
+  [key: string]: void;
 
 }
 declare const cssExports: CssExports;

test/verify-invalid-declaration/__snapshots__/verify-invalid-declaration.test.js.snap

@@ -6,12 +6,18 @@ exports[`Can error on invalid declaration 1`] = `
    // This file is automatically generated.
    // Please do not change this file!
    interface CssExports {
-     'classInBothFiles': string;
+ -   'classInBothFiles': string;
  -   'classInTypeScriptFile': string;
+ - }
+ - declare const cssExports: CssExports;
+ - export = cssExports;
+ - 
+ +   [key: string]: void;
+ +   'classInBothFiles': string;
  +   'classInCssFile': string;
-   }
-   declare const cssExports: CssExports;
-   export = cssExports;
+ + }
+ + declare const cssExports: CssExports;
+ + export = cssExports;
    
 
 "

test/verify-valid-declaration/index.css.d.ts

@@ -1,6 +1,7 @@
 // This file is automatically generated.
 // Please do not change this file!
 interface CssExports {
+  [key: string]: void;
   'hyphened-classname': string;
   'otherClass': string;
   'someClass': string;