fix: MP3 file test for Text-to-Speech SSML addresses [(#2378)](GoogleCloudPlatform/python-docs-samples#2378)

* fix: refactored MP3 file tests

* fix: moving resources to cloud-client/resources

* fix: removing expected_example.mp3

Author: crowdus

samples/resources/example.ssml

@@ -0,0 +1,4 @@
+<speak>123 Street Ln, Small Town, IL 12345 USA
+<break time="2s"/>1 Jenny St &amp; Number St, Tutone City, CA 86753
+<break time="2s"/>1 Piazza del Fibonacci, 12358 Pisa, Italy
+<break time="2s"/></speak>

samples/resources/example.txt

@@ -0,0 +1,3 @@
+123 Street Ln, Small Town, IL 12345 USA
+1 Jenny St & Number St, Tutone City, CA 86753
+1 Piazza del Fibonacci, 12358 Pisa, Italy

samples/ssml_addresses.py

@@ -0,0 +1,112 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+# [START tts_ssml_address_imports]
+from google.cloud import texttospeech
+
+import html
+# [END tts_ssml_address_imports]
+
+
+# [START tts_ssml_address_audio]
+def ssml_to_audio(ssml_text, outfile):
+    # Generates SSML text from plaintext.
+    #
+    # Given a string of SSML text and an output file name, this function
+    # calls the Text-to-Speech API. The API returns a synthetic audio
+    # version of the text, formatted according to the SSML commands. This
+    # function saves the synthetic audio to the designated output file.
+    #
+    # Args:
+    # ssml_text: string of SSML text
+    # outfile: string name of file under which to save audio output
+    #
+    # Returns:
+    # nothing
+
+    # Instantiates a client
+    client = texttospeech.TextToSpeechClient()
+
+    # Sets the text input to be synthesized
+    synthesis_input = texttospeech.types.SynthesisInput(ssml=ssml_text)
+
+    # Builds the voice request, selects the language code ("en-US") and
+    # the SSML voice gender ("MALE")
+    voice = texttospeech.types.VoiceSelectionParams(
+        language_code='en-US',
+        ssml_gender=texttospeech.enums.SsmlVoiceGender.MALE)
+
+    # Selects the type of audio file to return
+    audio_config = texttospeech.types.AudioConfig(
+        audio_encoding=texttospeech.enums.AudioEncoding.MP3)
+
+    # Performs the text-to-speech request on the text input with the selected
+    # voice parameters and audio file type
+    response = client.synthesize_speech(synthesis_input, voice, audio_config)
+
+    # Writes the synthetic audio to the output file.
+    with open(outfile, 'wb') as out:
+        out.write(response.audio_content)
+        print('Audio content written to file ' + outfile)
+    # [END tts_ssml_address_audio]
+
+
+# [START tts_ssml_address_ssml]
+def text_to_ssml(inputfile):
+    # Generates SSML text from plaintext.
+    # Given an input filename, this function converts the contents of the text
+    # file into a string of formatted SSML text. This function formats the SSML
+    # string so that, when synthesized, the synthetic audio will pause for two
+    # seconds between each line of the text file. This function also handles
+    # special text characters which might interfere with SSML commands.
+    #
+    # Args:
+    # inputfile: string name of plaintext file
+    #
+    # Returns:
+    # A string of SSML text based on plaintext input
+
+    # Parses lines of input file
+    with open(inputfile, 'r') as f:
+        raw_lines = f.read()
+
+    # Replace special characters with HTML Ampersand Character Codes
+    # These Codes prevent the API from confusing text with
+    # SSML commands
+    # For example, '<' --> '&lt;' and '&' --> '&amp;'
+
+    escaped_lines = html.escape(raw_lines)
+
+    # Convert plaintext to SSML
+    # Wait two seconds between each address
+    ssml = '<speak>{}</speak>'.format(
+        escaped_lines.replace('\n', '\n<break time="2s"/>'))
+
+    # Return the concatenated string of ssml script
+    return ssml
+# [END tts_ssml_address_ssml]
+
+
+# [START tts_ssml_address_test]
+def main():
+    # test example address file
+    plaintext = 'resources/example.txt'
+    ssml_text = text_to_ssml(plaintext)
+    ssml_to_audio(ssml_text, 'resources/example.mp3')
+    # [END tts_ssml_address_test]
+
+
+if __name__ == '__main__':
+    main()

samples/ssml_addresses_test.py

@@ -0,0 +1,49 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ssml_addresses import text_to_ssml
+from ssml_addresses import ssml_to_audio
+
+import filecmp
+import os
+
+
+def test_text_to_ssml(capsys):
+
+    # Read expected SSML output from resources
+    with open('resources/example.ssml', 'r') as f:
+        expected_ssml = f.read()
+
+    # Assert plaintext converted to SSML
+    input_text = 'resources/example.txt'
+    tested_ssml = text_to_ssml(input_text)
+    assert expected_ssml == tested_ssml
+
+
+def test_ssml_to_audio(capsys):
+
+    # Read SSML input from resources
+    with open('resources/example.ssml', 'r') as f:
+        input_ssml = f.read()
+
+    # Assert audio file generated
+    ssml_to_audio(input_ssml, 'test_example.mp3')
+    out, err = capsys.readouterr()
+
+    # Assert MP3 file created
+    assert os.path.isfile('test_example.mp3')
+    assert "Audio content written to file test_example.mp3" in out
+
+    # Delete MP3 test file
+    os.remove("test_example.mp3")