Allow leading underscore in sketch filenames

The Arduino Sketch Specification defines the allowed format of sketch folder names and sketch code filenames. Arduino
IDE enforces compliance with the specification in order to ensure sketches created with Arduino IDE can be used with any
other Arduino development tool.

The Arduino Sketch Specification has been changed to allow a leading underscore in sketch folder names and sketch code
filenames so IDE's sketch name validation must be updated accordingly.

arduino-ide-extension/src/common/protocol/sketches-service.ts

@@ -157,8 +157,6 @@ export namespace Sketch {
   // (non-API) exported for the tests
   export const defaultSketchFolderName = 'sketch';
   // (non-API) exported for the tests
-  export const defaultFallbackFirstChar = '0';
-  // (non-API) exported for the tests
   export const defaultFallbackChar = '_';
   // (non-API) exported for the tests
   export function reservedFilename(name: string): string {
@@ -176,11 +174,11 @@ export namespace Sketch {
   // (non-API) exported for the tests
   export const invalidSketchFolderNameMessage = nls.localize(
     'arduino/sketch/invalidSketchName',
-    'The name must start with a letter or number, followed by letters, numbers, dashes, dots and underscores. Maximum length is 63 characters.'
+    'The name must start with a letter, number, or underscore, followed by letters, numbers, dashes, dots and underscores. Maximum length is 63 characters.'
   );
   const invalidCloudSketchFolderNameMessage = nls.localize(
     'arduino/sketch/invalidCloudSketchName',
-    'The name must start with a letter or number, followed by letters, numbers, dashes, dots and underscores. Maximum length is 36 characters.'
+    'The name must start with a letter, number, or underscore, followed by letters, numbers, dashes, dots and underscores. Maximum length is 36 characters.'
   );
   /**
    * `undefined` if the candidate sketch folder name is valid. Otherwise, the validation error message.
@@ -193,7 +191,7 @@ export namespace Sketch {
     if (validFilenameError) {
       return validFilenameError;
     }
-    return /^[0-9a-zA-Z]{1}[0-9a-zA-Z_\.-]{0,62}$/.test(candidate)
+    return /^[0-9a-zA-Z_]{1}[0-9a-zA-Z_\.-]{0,62}$/.test(candidate)
       ? undefined
       : invalidSketchFolderNameMessage;
   }
@@ -208,7 +206,7 @@ export namespace Sketch {
     if (validFilenameError) {
       return validFilenameError;
     }
-    return /^[0-9a-zA-Z]{1}[0-9a-zA-Z_\.-]{0,35}$/.test(candidate)
+    return /^[0-9a-zA-Z_]{1}[0-9a-zA-Z_\.-]{0,35}$/.test(candidate)
       ? undefined
       : invalidCloudSketchFolderNameMessage;
   }
@@ -252,10 +250,7 @@ export namespace Sketch {
       return defaultSketchFolderName;
     }
     const validName = candidate
-      ? candidate
+      ? candidate.replace(/[^0-9a-zA-Z_]/g, defaultFallbackChar).slice(0, 63)
-          .replace(/^[^0-9a-zA-Z]{1}/g, defaultFallbackFirstChar)
-          .replace(/[^0-9a-zA-Z_]/g, defaultFallbackChar)
-          .slice(0, 63)
       : defaultSketchFolderName;
     if (appendTimestampSuffix) {
       return `${validName.slice(0, 63 - timestampSuffixLength)}${
@@ -283,10 +278,7 @@ export namespace Sketch {
       return defaultSketchFolderName;
     }
     return candidate
-      ? candidate
+      ? candidate.replace(/[^0-9a-zA-Z_]/g, defaultFallbackChar).slice(0, 36)
-          .replace(/^[^0-9a-zA-Z]{1}/g, defaultFallbackFirstChar)
-          .replace(/[^0-9a-zA-Z_]/g, defaultFallbackChar)
-          .slice(0, 36)
       : defaultSketchFolderName;
   }
 

arduino-ide-extension/src/test/browser/workspace-commands.test.ts

@@ -171,22 +171,22 @@ describe('workspace-commands', () => {
     });
 
     it('code files cannot start with number (no extension)', async () => {
-      const actual = await testMe('_invalid');
+      const actual = await testMe('-invalid');
       expect(actual).to.be.equal(Sketch.invalidSketchFolderNameMessage);
     });
 
     it('code files cannot start with number (trailing dot)', async () => {
-      const actual = await testMe('_invalid.');
+      const actual = await testMe('-invalid.');
       expect(actual).to.be.equal(Sketch.invalidSketchFolderNameMessage);
     });
 
     it('code files cannot start with number (trailing dot)', async () => {
-      const actual = await testMe('_invalid.cpp');
+      const actual = await testMe('-invalid.cpp');
       expect(actual).to.be.equal(Sketch.invalidSketchFolderNameMessage);
     });
 
     it('should warn about invalid extension first', async () => {
-      const actual = await testMe('_invalid.xxx');
+      const actual = await testMe('-invalid.xxx');
       expect(actual).to.be.equal(invalidExtensionMessage('.xxx'));
     });
 
@@ -196,7 +196,7 @@ describe('workspace-commands', () => {
     });
 
     it('should ignore non-code filename validation from the spec', async () => {
-      const actual = await testMe('_invalid.json');
+      const actual = await testMe('-invalid.json');
       expect(actual).to.be.empty;
     });
 

arduino-ide-extension/src/test/common/sketches-service.test.ts

@@ -43,7 +43,7 @@ describe('sketch', () => {
         ['trailing.dots...', false],
         ['no.trailing.dots.._', true],
         ['No Spaces', false],
-        ['_invalidToStartWithUnderscore', false],
+        ['_validToStartWithUnderscore', true],
         ['Invalid+Char.ino', false],
         ['', false],
         ['/', false],
@@ -81,7 +81,7 @@ describe('sketch', () => {
         ['can.contain.dots', true],
         ['-cannot-start-with-dash', false],
         ['.cannot.start.with.dash', false],
-        ['_cannot_start_with_underscore', false],
+        ['_can_start_with_underscore', true],
         ['No Spaces', false],
         ['Invalid+Char.ino', false],
         ['', false],
@@ -108,14 +108,14 @@ describe('sketch', () => {
   describe('toValidSketchFolderName', () => {
     [
       ['', Sketch.defaultSketchFolderName],
-      [' ', Sketch.defaultFallbackFirstChar],
+      [' ', Sketch.defaultFallbackChar],
-      ['  ', Sketch.defaultFallbackFirstChar + Sketch.defaultFallbackChar],
+      ['  ', Sketch.defaultFallbackChar + Sketch.defaultFallbackChar],
       [
         '0123456789012345678901234567890123456789012345678901234567890123',
         '012345678901234567890123456789012345678901234567890123456789012',
       ],
       ['foo bar', 'foo_bar'],
-      ['_foobar', '0foobar'],
+      ['-foobar', '_foobar'],
       ['vAlid', 'vAlid'],
       ['COM1', Sketch.defaultSketchFolderName],
       ['COM1.', 'COM1_'],
@@ -130,20 +130,18 @@ describe('sketch', () => {
     const epochSuffix = Sketch.timestampSuffix(epoch);
     [
       ['', Sketch.defaultSketchFolderName + epochSuffix],
-      [' ', Sketch.defaultFallbackFirstChar + epochSuffix],
+      [' ', Sketch.defaultFallbackChar + epochSuffix],
       [
         '  ',
-        Sketch.defaultFallbackFirstChar +
+        Sketch.defaultFallbackChar + Sketch.defaultFallbackChar + epochSuffix,
-          Sketch.defaultFallbackChar +
-          epochSuffix,
       ],
       [
         '0123456789012345678901234567890123456789012345678901234567890123',
         '0123456789012345678901234567890123456789012' + epochSuffix,
       ],
       ['foo bar', 'foo_bar' + epochSuffix],
-      ['.foobar', '0foobar' + epochSuffix],
+      ['.foobar', '_foobar' + epochSuffix],
-      ['-fooBar', '0fooBar' + epochSuffix],
+      ['-fooBar', '_fooBar' + epochSuffix],
       ['foobar.', 'foobar_' + epochSuffix],
       ['fooBar-', 'fooBar_' + epochSuffix],
       ['fooBar+', 'fooBar_' + epochSuffix],
@@ -164,19 +162,17 @@ describe('sketch', () => {
       ['only_underscore-is+ok.ino', 'only_underscore_is_ok_ino'],
       ['regex++', 'regex__'],
       ['dots...', 'dots___'],
-      ['.dots...', '0dots___'],
+      ['.dots...', '_dots___'],
-      ['-dashes---', '0dashes___'],
+      ['-dashes---', '_dashes___'],
-      ['_underscore___', '0underscore___'],
       ['No Spaces', 'No_Spaces'],
-      ['_startsWithUnderscore', '0startsWithUnderscore'],
       ['Invalid+Char.ino', 'Invalid_Char_ino'],
       ['', 'sketch'],
-      ['/', '0'],
+      ['/', '_'],
       [
         '/-1////////////////////+//////////////-/',
-        '0_1_________________________________',
+        '__1_________________________________',
       ],
-      ['//trash/', '0_trash_'],
+      ['//trash/', '__trash_'],
       [
         '63Length_012345678901234567890123456789012345678901234567890123',
         '63Length_012345678901234567890123456',

i18n/en.json

@@ -419,11 +419,11 @@
       "editInvalidSketchFolderLocationQuestion": "Do you want to try saving the sketch to a different location?",
       "editInvalidSketchFolderQuestion": "Do you want to try saving the sketch with a different name?",
       "exportBinary": "Export Compiled Binary",
-      "invalidCloudSketchName": "The name must start with a letter or number, followed by letters, numbers, dashes, dots and underscores. Maximum length is 36 characters.",
+      "invalidCloudSketchName": "The name must start with a letter, number, or underscore, followed by letters, numbers, dashes, dots and underscores. Maximum length is 36 characters.",
       "invalidSketchFolderLocationDetails": "You cannot save a sketch into a folder inside itself.",
       "invalidSketchFolderLocationMessage": "Invalid sketch folder location: '{0}'",
       "invalidSketchFolderNameMessage": "Invalid sketch folder name: '{0}'",
-      "invalidSketchName": "The name must start with a letter or number, followed by letters, numbers, dashes, dots and underscores. Maximum length is 63 characters.",
+      "invalidSketchName": "The name must start with a letter, number, or underscore, followed by letters, numbers, dashes, dots and underscores. Maximum length is 63 characters.",
       "moving": "Moving",
       "movingMsg": "The file \"{0}\" needs to be inside a sketch folder named \"{1}\".\nCreate this folder, move the file, and continue?",
       "new": "New Sketch",