diff --git a/src/vs/workbench/parts/debug/test/browser/debugANSIHandling.test.ts b/src/vs/workbench/parts/debug/test/browser/debugANSIHandling.test.ts
new file mode 100644
index 0000000000000000000000000000000000000000..33ff66b007718b91b007c7c953e2d2e3a2ded54f
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+++ b/src/vs/workbench/parts/debug/test/browser/debugANSIHandling.test.ts
@@ -0,0 +1,266 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import * as dom from 'vs/base/browser/dom';
+import { generateUuid } from 'vs/base/common/uuid';
+import { appendStylizedStringToContainer, handleANSIOutput } from 'vs/workbench/parts/debug/browser/debugANSIHandling';
+import { TestInstantiationService } from 'vs/platform/instantiation/test/common/instantiationServiceMock';
+import { workbenchInstantiationService } from 'vs/workbench/test/workbenchTestServices';
+import { LinkDetector } from 'vs/workbench/parts/debug/browser/linkDetector';
+
+suite('Debug - ANSI Handling', () => {
+
+	let linkDetector: LinkDetector;
+
+	/**
+	 * Instantiate a {@link LinkDetector} for use by the functions being tested.
+	 */
+	setup(() => {
+		const instantiationService: TestInstantiationService = <TestInstantiationService>workbenchInstantiationService();
+		linkDetector = instantiationService.createInstance(LinkDetector);
+	});
+
+	// todo: function here
+
+	test('appendStylizedStringToContainer', () => {
+		const root: HTMLSpanElement = document.createElement('span');
+		let child: Node;
+
+		assert.equal(0, root.children.length);
+
+		appendStylizedStringToContainer(root, 'content1', ['class1', 'class2'], linkDetector);
+		appendStylizedStringToContainer(root, 'content2', ['class2', 'class3'], linkDetector);
+
+		assert.equal(2, root.children.length);
+
+		child = root.firstChild;
+		if (child instanceof HTMLSpanElement) {
+			assert.equal('content1', child.textContent);
+			assert(dom.hasClass(child, 'class1'));
+			assert(dom.hasClass(child, 'class2'));
+		} else {
+			assert.fail();
+		}
+
+		child = root.lastChild;
+		if (child instanceof HTMLSpanElement) {
+			assert.equal('content2', child.textContent);
+			assert(dom.hasClass(child, 'class2'));
+			assert(dom.hasClass(child, 'class3'));
+		} else {
+			assert.fail();
+		}
+	});
+
+	/**
+	 * Apply an ANSI sequence to {@link #getSequenceOutput}.
+	 *
+	 * @param sequence The ANSI sequence to stylize.
+	 * @returns An {@link HTMLSpanElement} that contains the stylized text.
+	 */
+	function getSequenceOutput(sequence: string): HTMLSpanElement {
+		const root: HTMLSpanElement = handleANSIOutput(sequence, linkDetector);
+		assert.equal(1, root.children.length);
+		const child: Node = root.lastChild;
+		if (child instanceof HTMLSpanElement) {
+			return child;
+		} else {
+			assert.fail();
+			return null;
+		}
+	}
+
+	/**
+	 * Assert that a given ANSI sequence maintains added content following the ANSI code, and that
+	 * the provided {@param assertion} passes.
+	 *
+	 * @param sequence The ANSI sequence to verify. The provided sequence should contain ANSI codes
+	 * only, and should not include actual text content as it is provided by this function.
+	 * @param assertion The function used to verify the output.
+	 */
+	function assertSingleSequenceElement(sequence: string, assertion: (child: HTMLSpanElement) => void): void {
+		const child: HTMLSpanElement = getSequenceOutput(sequence + 'content');
+		assert.equal('content', child.textContent);
+		assertion(child);
+	}
+
+	test('Expected single sequence operation', () => {
+
+		// Bold code
+		assertSingleSequenceElement('\x1b[1m', (child) => {
+			assert(dom.hasClass(child, 'code-bold'));
+		});
+
+		// Underline code
+		assertSingleSequenceElement('\x1b[4m', (child) => {
+			assert(dom.hasClass(child, 'code-underline'));
+		});
+
+		for (let i = 30; i <= 37; i++) {
+			const style: string = 'code-foreground-' + i;
+
+			// Foreground colour codes
+			assertSingleSequenceElement('\x1b[' + i + 'm', (child) => {
+				assert(dom.hasClass(child, style));
+			});
+
+			// Cancellation code removes colour code
+			assertSingleSequenceElement('\x1b[' + i + ';39m', (child) => {
+				assert(dom.hasClass(child, style) === false);
+			});
+		}
+
+		// Codes do not interfere
+		assertSingleSequenceElement('\x1b[1;4;30;31;32;33;34;35;36;37m', (child) => {
+			assert.equal(10, child.classList.length);
+
+			assert(dom.hasClass(child, 'code-bold'));
+			assert(dom.hasClass(child, 'code-underline'));
+			for (let i = 30; i <= 37; i++) {
+				assert(dom.hasClass(child, 'code-foreground-' + i));
+			}
+		});
+
+		// Duplicate codes do not change output
+		assertSingleSequenceElement('\x1b[1;1;4;1;4;4;1;4m', (child) => {
+			assert(dom.hasClass(child, 'code-bold'));
+			assert(dom.hasClass(child, 'code-underline'));
+		});
+
+		// Extra terminating semicolon does not change output
+		assertSingleSequenceElement('\x1b[1;4;m', (child) => {
+			assert(dom.hasClass(child, 'code-bold'));
+			assert(dom.hasClass(child, 'code-underline'));
+		});
+
+		// Cancellation code removes all codes
+		assertSingleSequenceElement('\x1b[1;4;30;31;32;33;34;35;36;37;0m', (child) => {
+			assert.equal(0, child.classList.length);
+		});
+
+	});
+
+	/**
+	 * Assert that a given ANSI sequence produces the expected number of {@link HTMLSpanElement} children. For
+	 * each child, run the provided assertion.
+	 *
+	 * @param sequence The ANSI sequence to verify.
+	 * @param assertions A set of assertions to run on the resulting children.
+	 */
+	function assertMultipleSequenceElements(sequence: string, assertions: Array<(child: HTMLSpanElement) => void>): void {
+		const root: HTMLSpanElement = handleANSIOutput(sequence, linkDetector);
+		assert.equal(assertions.length, root.children.length);
+		for (let i = 0; i < assertions.length; i++) {
+			const child: Node = root.children[i];
+			if (child instanceof HTMLSpanElement) {
+				assertions[i](child);
+			} else {
+				assert.fail();
+			}
+		}
+	}
+
+	test('Expected multiple sequence operation', () => {
+
+		// Multiple codes affect the same text
+		assertSingleSequenceElement('\x1b[1m\x1b[4m\x1b[32m', (child) => {
+			assert(dom.hasClass(child, 'code-bold'));
+			assert(dom.hasClass(child, 'code-underline'));
+			assert(dom.hasClass(child, 'code-foreground-32'));
+		});
+
+		// Consecutive codes do not affect previous ones
+		assertMultipleSequenceElements('\x1b[1mbold\x1b[32mgreen\x1b[4munderline\x1b[0mnothing', [
+			(bold) => {
+				assert.equal(1, bold.classList.length);
+				assert(dom.hasClass(bold, 'code-bold'));
+			},
+			(green) => {
+				assert.equal(2, green.classList.length);
+				assert(dom.hasClass(green, 'code-bold'));
+				assert(dom.hasClass(green, 'code-foreground-32'));
+			},
+			(underline) => {
+				assert.equal(3, underline.classList.length);
+				assert(dom.hasClass(underline, 'code-bold'));
+				assert(dom.hasClass(underline, 'code-foreground-32'));
+				assert(dom.hasClass(underline, 'code-underline'));
+			},
+			(nothing) => {
+				assert.equal(0, nothing.classList.length);
+			},
+		]);
+
+	});
+
+	/**
+	 * Assert that the provided ANSI sequence exactly matches the text content of the resulting
+	 * {@link HTMLSpanElement}.
+	 *
+	 * @param sequence The ANSI sequence to verify.
+	 */
+	function assertSequenceEqualToContent(sequence: string): void {
+		const child: HTMLSpanElement = getSequenceOutput(sequence);
+		assert(child.textContent === sequence);
+	}
+
+	test('Invalid codes treated as regular text', () => {
+
+		// Individual components of ANSI code start are printed
+		assertSequenceEqualToContent('\x1b');
+		assertSequenceEqualToContent('[');
+
+		// Unsupported sequence prints both characters
+		assertSequenceEqualToContent('\x1b[');
+
+		// Random strings are displayed properly
+		for (let i = 0; i < 50; i++) {
+			const uuid: string = generateUuid();
+			assertSequenceEqualToContent(uuid);
+		}
+
+	});
+
+	/**
+	 * Assert that a given ANSI sequence maintains added content following the ANSI code, and that
+	 * the expression itself is thrown away.
+	 *
+	 * @param sequence The ANSI sequence to verify. The provided sequence should contain ANSI codes
+	 * only, and should not include actual text content as it is provided by this function.
+	 */
+	function assertEmptyOutput(sequence: string) {
+		const child: HTMLSpanElement = getSequenceOutput(sequence + 'content');
+		assert.equal('content', child.textContent);
+		assert.equal(0, child.classList.length);
+	}
+
+	test('Empty sequence output', () => {
+
+		const sequences: string[] = [
+			// No colour codes
+			'',
+			'\x1b[;m',
+			'\x1b[1;;m',
+			'\x1b[m',
+			// Unsupported colour codes
+			'\x1b[30;40m',
+			'\x1b[100m'
+		];
+
+		sequences.forEach(sequence => {
+			assertEmptyOutput(sequence);
+		});
+
+		// Check other possible ANSI terminators
+		const terminators: string[] = 'ABCDHIJKfhmpsu'.split('');
+
+		terminators.forEach(terminator => {
+			assertEmptyOutput('\x1b[content' + terminator);
+		});
+
+	});
+
+});
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