Don't truncate output of printType (#154)

Author: skarab42

source/lib/assertions/handlers/informational.ts

@@ -1,7 +1,17 @@
-import {CallExpression, TypeChecker} from '@tsd/typescript';
+import {CallExpression, TypeChecker, TypeFormatFlags} from '@tsd/typescript';
 import {Diagnostic} from '../../interfaces';
 import {makeDiagnostic} from '../../utils';
 
+/**
+ * Default formatting flags set by TS plus the {@link TypeFormatFlags.NoTruncation NoTruncation} flag.
+ *
+ * @see {@link https://github.dev/microsoft/TypeScript/blob/b975dfa1027d1f3073fa7cbe6f7045bf4c882785/src/compiler/checker.ts#L4717 TypeChecker.typeToString}
+ */
+const typeToStringFormatFlags =
+	TypeFormatFlags.AllowUniqueESSymbolType |
+	TypeFormatFlags.UseAliasDefinedOutsideCurrentScope |
+	TypeFormatFlags.NoTruncation;
+
 /**
  * Prints the type of the argument of the assertion as a warning.
  *
@@ -19,8 +29,9 @@ export const prinTypeWarning = (checker: TypeChecker, nodes: Set<CallExpression>
 	for (const node of nodes) {
 		const argumentType = checker.getTypeAtLocation(node.arguments[0]);
 		const argumentExpression = node.arguments[0].getText();
+		const typeString = checker.typeToString(argumentType, node, typeToStringFormatFlags);
 
-		diagnostics.push(makeDiagnostic(node, `Type for expression \`${argumentExpression}\` is: \`${checker.typeToString(argumentType)}\``, 'warning'));
+		diagnostics.push(makeDiagnostic(node, `Type for expression \`${argumentExpression}\` is: \`${typeString}\``, 'warning'));
 	}
 
 	return diagnostics;

source/test/fixtures/print-type/index.d.ts

@@ -1 +1,17 @@
-export default function (foo: number): number | null;
+export function aboveZero(foo: number): number | null;
+
+type SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace = {
+	life: 42
+};
+
+export const bigType: {
+	prop1: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop2: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop3: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop4: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop5: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop6: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop7: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop8: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+	prop9: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace;
+}

source/test/fixtures/print-type/index.test-d.ts

@@ -1,5 +1,5 @@
 import {printType} from '../../..';
-import aboveZero from '.';
+import {aboveZero, bigType} from '.';
 
 printType(aboveZero);
 printType(null);
@@ -8,3 +8,4 @@ printType(null as any);
 printType(null as never);
 printType(null as unknown);
 printType('foo');
+printType(bigType);

source/test/test.ts

@@ -453,6 +453,7 @@ test('prints the types of expressions passed to `printType` helper', async t =>
 		[8, 0, 'warning', 'Type for expression `null as never` is: `never`'],
 		[9, 0, 'warning', 'Type for expression `null as unknown` is: `unknown`'],
 		[10, 0, 'warning', 'Type for expression `\'foo\'` is: `"foo"`'],
+		[11, 0, 'warning', 'Type for expression `bigType` is: `{ prop1: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop2: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop3: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop4: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop5: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop6: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop7: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop8: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; prop9: SuperTypeWithAnExessiveLongNameThatTakesUpTooMuchSpace; }`']
 	]);
 });