feat: return type check errors (#446)

Author: camc314

cmd/tsgolint/headless.go

@@ -373,6 +373,10 @@ func runHeadless(args []string) int {
 			Fix:            fix,
 			FixSuggestions: fixSuggestions,
 		},
+		linter.TypeErrors{
+			ReportSyntactic: payload.ReportSyntactic,
+			ReportSemantic:  payload.ReportSemantic,
+		},
 	)
 
 	close(diagnosticsChan)

cmd/tsgolint/main.go

@@ -16,6 +16,7 @@ import (
 	"time"
 	"unicode"
 
+	"github.com/typescript-eslint/tsgolint/internal/diagnostic"
 	"github.com/typescript-eslint/tsgolint/internal/linter"
 	"github.com/typescript-eslint/tsgolint/internal/rule"
 	"github.com/typescript-eslint/tsgolint/internal/utils"
@@ -479,10 +480,17 @@ func runMain() int {
 		func(d rule.RuleDiagnostic) {
 			diagnosticsChan <- d
 		},
+		func(d diagnostic.Internal) {
+			// Internal diagnostics are not used in this mode
+		},
 		linter.Fixes{
 			Fix:            true,
 			FixSuggestions: true,
 		},
+		linter.TypeErrors{
+			ReportSyntactic: false,
+			ReportSemantic:  false,
+		},
 	)
 
 	close(diagnosticsChan)

cmd/tsgolint/payload.go

@@ -21,6 +21,8 @@ type headlessPayload struct {
 	Version         int               `json:"version"` // version must be 2
 	Configs         []headlessConfig  `json:"configs"`
 	SourceOverrides map[string]string `json:"source_overrides,omitempty"`
+	ReportSyntactic bool              `json:"report_syntactic,omitempty"`
+	ReportSemantic  bool              `json:"report_semantic,omitempty"`
 }
 
 type headlessConfig struct {

e2e/__snapshots__/snapshot.test.ts.snap

@@ -3966,6 +3966,23 @@ exports[`TSGoLint E2E Snapshot Tests > should report an error if the tsconfig.js
 ]
 `;
 
+exports[`TSGoLint E2E Snapshot Tests > should report type errors 1`] = `
+[
+  {
+    "file_path": "fixtures/report-type-errors/index.ts",
+    "kind": 1,
+    "message": {
+      "description": "Type 'number' is not assignable to type 'string'.",
+      "id": "TS2322",
+    },
+    "range": {
+      "end": 7,
+      "pos": 6,
+    },
+  },
+]
+`;
+
 exports[`TSGoLint E2E Snapshot Tests > should work correctly with nested module namespaces and parent module searches (\`ValueMatchesSomeSpecifier\`) (issue #135) 1`] = `[]`;
 
 exports[`TSGoLint E2E Snapshot Tests > supports passing rule config 1`] = `

e2e/fixtures/report-type-errors/index.ts

@@ -0,0 +1 @@
+const x: string = 123;

e2e/fixtures/report-type-errors/tsconfig.json

@@ -0,0 +1 @@
+{}

e2e/snapshot.test.ts

@@ -189,6 +189,10 @@ function generateConfig(
   rules:
     readonly ((typeof ALL_RULES)[number] | { name: typeof ALL_RULES[number]; options: Record<string, unknown> })[] =
       ALL_RULES,
+  options?: {
+    reportSyntactic?: boolean;
+    reportSemantic?: boolean;
+  },
 ): string {
   // Headless payload format:
   // ```json
@@ -212,6 +216,8 @@ function generateConfig(
         } => (typeof r === 'string' ? { name: r } : r)),
       },
     ],
+    ...(options?.reportSyntactic !== undefined && { report_syntactic: options.reportSyntactic }),
+    ...(options?.reportSemantic !== undefined && { report_semantic: options.reportSemantic }),
   } as const;
   return JSON.stringify(config);
 }
@@ -535,4 +541,27 @@ console.log(x);
 
     expect(diagnostics).toMatchSnapshot();
   });
+
+  it('should report type errors', async () => {
+    const testFiles = await getTestFiles('report-type-errors');
+    expect(testFiles.length).toBeGreaterThan(0);
+
+    const config = generateConfig(
+      testFiles,
+      ['no-floating-promises'],
+      {
+        reportSemantic: true,
+      },
+    );
+
+    const output = execFileSync(TSGOLINT_BIN, ['headless'], {
+      input: config,
+      env: { ...process.env, GOMAXPROCS: '1' },
+    });
+
+    let diagnostics = parseHeadlessOutput(output);
+    diagnostics = sortDiagnostics(diagnostics);
+
+    expect(diagnostics).toMatchSnapshot();
+  });
 });

internal/linter/linter.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"strconv"
 	"strings"
 
 	"github.com/typescript-eslint/tsgolint/internal/diagnostic"
@@ -34,6 +35,11 @@ type Fixes struct {
 	FixSuggestions bool
 }
 
+type TypeErrors struct {
+	ReportSyntactic bool
+	ReportSemantic  bool
+}
+
 func RunLinter(
 	logLevel utils.LogLevel,
 	currentDirectory string,
@@ -44,6 +50,7 @@ func RunLinter(
 	onRuleDiagnostic func(diagnostic rule.RuleDiagnostic),
 	onInternalDiagnostic func(d diagnostic.Internal),
 	fixState Fixes,
+	typeErrors TypeErrors,
 ) error {
 
 	idx := 0
@@ -99,7 +106,7 @@ func RunLinter(
 			panic(fmt.Sprintf("Expected file '%s' to be in program '%s'", unmatchedFilesString, configFileName))
 		}
 
-		err = RunLinterOnProgram(logLevel, program, sourceFiles, workers, getRulesForFile, onRuleDiagnostic, fixState)
+		err = RunLinterOnProgram(logLevel, program, sourceFiles, workers, getRulesForFile, onRuleDiagnostic, onInternalDiagnostic, fixState, typeErrors)
 		if err != nil {
 			return err
 		}
@@ -130,7 +137,7 @@ func RunLinter(
 			files = append(files, sf)
 		}
 
-		err = RunLinterOnProgram(logLevel, program, files, workers, getRulesForFile, onRuleDiagnostic, fixState)
+		err = RunLinterOnProgram(logLevel, program, files, workers, getRulesForFile, onRuleDiagnostic, onInternalDiagnostic, fixState, typeErrors)
 		if err != nil {
 			return err
 		}
@@ -140,7 +147,7 @@ func RunLinter(
 
 }
 
-func RunLinterOnProgram(logLevel utils.LogLevel, program *compiler.Program, files []*ast.SourceFile, workers int, getRulesForFile func(sourceFile *ast.SourceFile) []ConfiguredRule, onDiagnostic func(diagnostic rule.RuleDiagnostic), fixState Fixes) error {
+func RunLinterOnProgram(logLevel utils.LogLevel, program *compiler.Program, files []*ast.SourceFile, workers int, getRulesForFile func(sourceFile *ast.SourceFile) []ConfiguredRule, onDiagnostic func(diagnostic rule.RuleDiagnostic), onInternalDiagnostic func(d diagnostic.Internal), fixState Fixes, typeErrors TypeErrors) error {
 	type checkerWorkload struct {
 		checker *checker.Checker
 		program *compiler.Program
@@ -157,6 +164,41 @@ func RunLinterOnProgram(logLevel utils.LogLevel, program *compiler.Program, file
 	program.BindSourceFiles()
 
 	ctx := core.WithRequestID(context.Background(), "__single_run__")
+
+	if typeErrors.ReportSyntactic || typeErrors.ReportSemantic {
+		for _, file := range files {
+			fileName := file.FileName()
+
+			if typeErrors.ReportSyntactic {
+				syntacticDiagnostics := program.GetSyntacticDiagnostics(ctx, file)
+				for _, d := range syntacticDiagnostics {
+					if d.File() != nil && d.File().FileName() == fileName {
+						onInternalDiagnostic(diagnostic.Internal{
+							Range:       d.Loc(),
+							Id:          "TS" + strconv.Itoa(int(d.Code())),
+							Description: d.Message(),
+							FilePath:    &fileName,
+						})
+					}
+				}
+			}
+
+			if typeErrors.ReportSemantic {
+				semanticDiagnostics := program.GetSemanticDiagnostics(ctx, file)
+				for _, d := range semanticDiagnostics {
+					if d.File() != nil && d.File().FileName() == fileName {
+						onInternalDiagnostic(diagnostic.Internal{
+							Range:       d.Loc(),
+							Id:          "TS" + strconv.Itoa(int(d.Code())),
+							Description: d.Message(),
+							FilePath:    &fileName,
+						})
+					}
+				}
+			}
+		}
+	}
+
 	program.ForEachCheckerParallel(ctx, func(idx int, ch *checker.Checker) {
 		flatQueue = append(flatQueue, checkerWorkload{ch, program, queue})
 	})

internal/rule_tester/rule_tester.go

@@ -10,6 +10,7 @@ import (
 	"github.com/microsoft/typescript-go/shim/ast"
 	"github.com/microsoft/typescript-go/shim/scanner"
 	"github.com/microsoft/typescript-go/shim/tspath"
+	"github.com/typescript-eslint/tsgolint/internal/diagnostic"
 	"github.com/typescript-eslint/tsgolint/internal/linter"
 	"github.com/typescript-eslint/tsgolint/internal/rule"
 	"github.com/typescript-eslint/tsgolint/internal/utils"
@@ -98,10 +99,17 @@ func RunRuleTester(rootDir string, tsconfigPath string, t *testing.T, r *rule.Ru
 
 				diagnostics = append(diagnostics, diagnostic)
 			},
+			func(d diagnostic.Internal) {
+				// Internal diagnostics are not used in rule tester
+			},
 			linter.Fixes{
 				Fix:            true,
 				FixSuggestions: true,
 			},
+			linter.TypeErrors{
+				ReportSyntactic: false,
+				ReportSemantic:  false,
+			},
 		)
 
 		assert.NilError(t, err, "error running linter. code:\n", code)

shim/ast/extra-shim.json

@@ -2,6 +2,13 @@
   "ExtraMethods": {
     "Node": [
       "Type"
+    ],
+    "Diagnostic": [
+      "File",
+      "Loc",
+      "Code",
+      "Category",
+      "Message"
     ]
   }
 }