Function expectFlatTreeToMatch

src/material/tree/tree.spec.ts:759–805

(
  treeElement: Element,
  expectedPaddingIndent: number = 28,
  ...expectedTree: TreeContent
)

}

function expectFlatTreeToMatch(
  treeElement: Element,
  expectedPaddingIndent: number = 28,
  ...expectedTree: TreeContent
) {
  const missedExpectations: string[] = [];

  function checkNode(node: Element, expectedNode: NodeContent) {
    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: NodeContent) {
    const rawLevel = (node as HTMLElement).style.paddingLeft;

    // Some browsers return 0, while others return 0px.
    const actualLevel = rawLevel === '0' ? '0px' : rawLevel;
    if (expectedNode.length === 1) {
      if (actualLevel !== `` && actualLevel !== '0px') {
        missedExpectations.push(`Expected node level to be 0px but was ${actualLevel}`);
      }
    } else {
      const expectedLevel = `${(expectedNode.length - 1) * expectedPaddingIndent}px`;
      if (actualLevel != expectedLevel) {
        missedExpectations.push(
          `Expected node level to be ${expectedLevel} but was ${actualLevel}`,
        );
      }
    }
  }

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

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

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

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