Function expectFlatTreeToMatch

src/cdk/tree/tree.spec.ts:1639–1678

(
  treeElement: Element,
  expectedPaddingIndent = 28,
  expectedPaddingUnits = 'px',
  ...expectedTree: any[]
)

}

function expectFlatTreeToMatch(
  treeElement: Element,
  expectedPaddingIndent = 28,
  expectedPaddingUnits = 'px',
  ...expectedTree: any[]
) {
  const missedExpectations: string[] = [];

  function checkNode(node: Element, expectedNode: any[]) {
    const actualTextContent = node.textContent!.trim();
    const expectedTextContent = expectedNode[expectedNode.length - 1];
    if (actualTextContent !== expectedTextContent) {
      missedExpectations.push(
        `Expected node contents to be ${expectedTextContent} but was ${actualTextContent}`,
      );
    }
  }

  function checkLevel(node: Element, expectedNode: any[]) {
    const rawLevel = (node as HTMLElement).style.paddingLeft;

    // Some browsers return 0, while others return 0px.
    const actualLevel = rawLevel === '0' ? '0px' : rawLevel;
    const expectedLevel = `${expectedNode.length * expectedPaddingIndent}${expectedPaddingUnits}`;
    if (actualLevel != expectedLevel) {
      missedExpectations.push(`Expected node level to be ${expectedLevel} but was ${actualLevel}`);
    }
  }

  getNodes(treeElement).forEach((node, index) => {
    const expected = expectedTree ? expectedTree[index] : null;

    checkLevel(node, expected);
    checkNode(node, expected);
  });

  if (missedExpectations.length) {
    fail(missedExpectations.join('\n'));
  }
}

function expectNestedTreeToMatch(treeElement: Element, ...expectedTree: any[]) {
  const missedExpectations: string[] = [];