1 files changed, 163 insertions, 0 deletions
diff --git a/testing/web-platform/tests/streams/transform-streams/lipfuzz.any.js b/testing/web-platform/tests/streams/transform-streams/lipfuzz.any.js
new file mode 100644
index 0000000000..f9f148aaf1
--- /dev/null
+++ b/testing/web-platform/tests/streams/transform-streams/lipfuzz.any.js
@@ -0,0 +1,163 @@
+// META: global=window,worker
+'use strict';
+
+class LipFuzzTransformer {
+  constructor(substitutions) {
+    this.substitutions = substitutions;
+    this.partialChunk = '';
+    this.lastIndex = undefined;
+  }
+
+  transform(chunk, controller) {
+    chunk = this.partialChunk + chunk;
+    this.partialChunk = '';
+    // lastIndex is the index of the first character after the last substitution.
+    this.lastIndex = 0;
+    chunk = chunk.replace(/\{\{([a-zA-Z0-9_-]+)\}\}/g, this.replaceTag.bind(this));
+    // Regular expression for an incomplete template at the end of a string.
+    const partialAtEndRegexp = /\{(\{([a-zA-Z0-9_-]+(\})?)?)?$/g;
+    // Avoid looking at any characters that have already been substituted.
+    partialAtEndRegexp.lastIndex = this.lastIndex;
+    this.lastIndex = undefined;
+    const match = partialAtEndRegexp.exec(chunk);
+    if (match) {
+      this.partialChunk = chunk.substring(match.index);
+      chunk = chunk.substring(0, match.index);
+    }
+    controller.enqueue(chunk);
+  }
+
+  flush(controller) {
+    if (this.partialChunk.length > 0) {
+      controller.enqueue(this.partialChunk);
+    }
+  }
+
+  replaceTag(match, p1, offset) {
+    let replacement = this.substitutions[p1];
+    if (replacement === undefined) {
+      replacement = '';
+    }
+    this.lastIndex = offset + replacement.length;
+    return replacement;
+  }
+}
+
+const substitutions = {
+  in1: 'out1',
+  in2: 'out2',
+  quine: '{{quine}}',
+  bogusPartial: '{{incompleteResult}'
+};
+
+const cases = [
+  {
+    input: [''],
+    output: ['']
+  },
+  {
+    input: [],
+    output: []
+  },
+  {
+    input: ['{{in1}}'],
+    output: ['out1']
+  },
+  {
+    input: ['z{{in1}}'],
+    output: ['zout1']
+  },
+  {
+    input: ['{{in1}}q'],
+    output: ['out1q']
+  },
+  {
+    input: ['{{in1}}{{in1}'],
+    output: ['out1', '{{in1}']
+  },
+  {
+    input: ['{{in1}}{{in1}', '}'],
+    output: ['out1', 'out1']
+  },
+  {
+    input: ['{{in1', '}}'],
+    output: ['', 'out1']
+  },
+  {
+    input: ['{{', 'in1}}'],
+    output: ['', 'out1']
+  },
+  {
+    input: ['{', '{in1}}'],
+    output: ['', 'out1']
+  },
+  {
+    input: ['{{', 'in1}'],
+    output: ['', '', '{{in1}']
+  },
+  {
+    input: ['{'],
+    output: ['', '{']
+  },
+  {
+    input: ['{', ''],
+    output: ['', '', '{']
+  },
+  {
+    input: ['{', '{', 'i', 'n', '1', '}', '}'],
+    output: ['', '', '', '', '', '', 'out1']
+  },
+  {
+    input: ['{{in1}}{{in2}}{{in1}}'],
+    output: ['out1out2out1']
+  },
+  {
+    input: ['{{wrong}}'],
+    output: ['']
+  },
+  {
+    input: ['{{wron', 'g}}'],
+    output: ['', '']
+  },
+  {
+    input: ['{{quine}}'],
+    output: ['{{quine}}']
+  },
+  {
+    input: ['{{bogusPartial}}'],
+    output: ['{{incompleteResult}']
+  },
+  {
+    input: ['{{bogusPartial}}}'],
+    output: ['{{incompleteResult}}']
+  }
+];
+
+for (const testCase of cases) {
+  const inputChunks = testCase.input;
+  const outputChunks = testCase.output;
+  promise_test(() => {
+    const lft = new TransformStream(new LipFuzzTransformer(substitutions));
+    const writer = lft.writable.getWriter();
+    const promises = [];
+    for (const inputChunk of inputChunks) {
+      promises.push(writer.write(inputChunk));
+    }
+    promises.push(writer.close());
+    const reader = lft.readable.getReader();
+    let readerChain = Promise.resolve();
+    for (const outputChunk of outputChunks) {
+      readerChain = readerChain.then(() => {
+        return reader.read().then(({ value, done }) => {
+          assert_false(done, `done should be false when reading ${outputChunk}`);
+          assert_equals(value, outputChunk, `value should match outputChunk`);
+        });
+      });
+    }
+    readerChain = readerChain.then(() => {
+      return reader.read().then(({ done }) => assert_true(done, `done should be true`));
+    });
+    promises.push(readerChain);
+    return Promise.all(promises);
+  }, `testing "${inputChunks}" (length ${inputChunks.length})`);
+}