Disable check diagnostics per line

Author: mhegazy

src/compiler/program.ts

@@ -4,6 +4,7 @@
 
 namespace ts {
     const emptyArray: any[] = [];
+    const suppressDiagnosticCommentRegEx = /(^\s*$)|(^\s*\/\/\/?\s*(@ts-suppress)?)/;
 
     export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean, configName = "tsconfig.json"): string {
         while (true) {
@@ -923,10 +924,36 @@ namespace ts {
                 const fileProcessingDiagnosticsInFile = fileProcessingDiagnostics.getDiagnostics(sourceFile.fileName);
                 const programDiagnosticsInFile = programDiagnostics.getDiagnostics(sourceFile.fileName);
 
-                return bindDiagnostics.concat(checkDiagnostics, fileProcessingDiagnosticsInFile, programDiagnosticsInFile);
+                const diagnostics = bindDiagnostics.concat(checkDiagnostics, fileProcessingDiagnosticsInFile, programDiagnosticsInFile);
+                return isSourceFileJavaScript(sourceFile)
+                    ? filter(diagnostics, shouldReportDiagnostic)
+                    : diagnostics;
             });
         }
 
+        /**
+         * Skip errors if previous line start with '// @ts-suppress' comment, not counting non-empty non-comment lines
+         */
+        function shouldReportDiagnostic(diagnostic: Diagnostic) {
+            const { file, start } = diagnostic;
+            const lineStarts = getLineStarts(file);
+            let { line } = computeLineAndCharacterOfPosition(lineStarts, start);
+            while (line > 0) {
+                const previousLineText = file.text.slice(lineStarts[line - 1], lineStarts[line]);
+                const result = suppressDiagnosticCommentRegEx.exec(previousLineText);
+                if (!result) {
+                    // non-empty line
+                    return true;
+                }
+                if (result[3]) {
+                    // @ts-suppress
+                    return false;
+                }
+                line--;
+            }
+            return true;
+        }
+
         function getJavaScriptSyntacticDiagnosticsForFile(sourceFile: SourceFile): Diagnostic[] {
             return runWithCancellationToken(() => {
                 const diagnostics: Diagnostic[] = [];

tests/baselines/reference/checkJsFiles_skipDiagnostics.symbols

@@ -0,0 +1,38 @@
+=== tests/cases/compiler/a.js ===
+
+var x = 0;
+>x : Symbol(x, Decl(a.js, 1, 3))
+
+
+/// @ts-suppress
+x();
+>x : Symbol(x, Decl(a.js, 1, 3))
+
+/// @ts-suppress
+x();
+>x : Symbol(x, Decl(a.js, 1, 3))
+
+/// @ts-suppress
+x(
+>x : Symbol(x, Decl(a.js, 1, 3))
+
+    2,
+    3);
+
+
+
+// @ts-suppress
+// come comment
+// some other comment
+
+// @anohter
+
+x();
+>x : Symbol(x, Decl(a.js, 1, 3))
+
+
+
+// @ts-suppress: no call signature
+x();
+>x : Symbol(x, Decl(a.js, 1, 3))
+

tests/baselines/reference/checkJsFiles_skipDiagnostics.types

@@ -0,0 +1,47 @@
+=== tests/cases/compiler/a.js ===
+
+var x = 0;
+>x : number
+>0 : 0
+
+
+/// @ts-suppress
+x();
+>x() : any
+>x : number
+
+/// @ts-suppress
+x();
+>x() : any
+>x : number
+
+/// @ts-suppress
+x(
+>x(    2,    3) : any
+>x : number
+
+    2,
+>2 : 2
+
+    3);
+>3 : 3
+
+
+
+// @ts-suppress
+// come comment
+// some other comment
+
+// @anohter
+
+x();
+>x() : any
+>x : number
+
+
+
+// @ts-suppress: no call signature
+x();
+>x() : any
+>x : number
+

tests/cases/compiler/checkJsFiles_skipDiagnostics.ts

@@ -0,0 +1,33 @@
+// @allowJs: true
+// @checkJs: true
+// @noEmit: true
+
+// @fileName: a.js
+var x = 0;
+
+
+/// @ts-suppress
+x();
+
+/// @ts-suppress
+x();
+
+/// @ts-suppress
+x(
+    2,
+    3);
+
+
+
+// @ts-suppress
+// come comment
+// some other comment
+
+// @anohter
+
+x();
+
+
+
+// @ts-suppress: no call signature
+x();