feat: extract the core package to a separate Gradle module

.github/workflows/code-quality-checks.yaml

@@ -17,9 +17,3 @@ jobs:
       - name: Run Checks
         id: build
         run: gradle clean build
-      - name: Upload Coverage Report
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: coverage-report
-          path: code/build/reports/kover

core/build.gradle

@@ -0,0 +1,89 @@
+import kotlinx.kover.gradle.plugin.dsl.AggregationType
+import kotlinx.kover.gradle.plugin.dsl.CoverageUnit
+
+plugins {
+    id 'org.jetbrains.kotlin.jvm' version '2.1.0'
+
+    /* Test Reporting */
+    id 'org.jetbrains.kotlinx.kover' version "0.9.0"
+
+    /* Linting */
+    id "org.jlleitschuh.gradle.ktlint" version "12.1.2"
+}
+
+kotlin {
+    jvmToolchain(8)
+}
+
+dependencies {
+    /* Kotlin */
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib:2.1.0'
+
+    /* EG SDK Core */
+    implementation 'com.squareup.okio:okio:3.10.2'
+    implementation 'com.ebay.ejmask:ejmask-api:1.3.0'
+    implementation 'com.ebay.ejmask:ejmask-extensions:1.3.0'
+    implementation 'com.fasterxml.jackson.core:jackson-databind:2.18.2'
+    implementation 'com.fasterxml.jackson.module:jackson-module-kotlin:2.18.2'
+    implementation 'org.slf4j:slf4j-api:2.0.16'
+
+    /* Testing */
+    testImplementation platform('org.junit:junit-bom:5.11.4')
+    testImplementation 'org.junit.jupiter:junit-jupiter-api'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
+    testImplementation 'org.junit.jupiter:junit-jupiter-params'
+    testImplementation 'io.mockk:mockk:1.13.14'
+    testImplementation "com.squareup.okhttp3:mockwebserver:4.12.0"
+}
+
+ktlint {
+    debug = true
+    version = "1.5.0"
+    verbose = true
+
+    additionalEditorconfig = [
+            "max_line_length": "200",
+            "indent_style": "space",
+            "indent_size": "4",
+            "insert_final_newline": "true",
+            "end_of_line": "lf",
+    ]
+}
+
+test {
+    useJUnitPlatform()
+
+    testLogging {
+        events "passed", "skipped", "failed"
+    }
+
+    classpath = classpath.filter {
+        // exclude original sdk.properties file during testing
+        !it.absolutePath.contains("build/resources/main/sdk.properties")
+    }
+}
+
+tasks.named("check") {
+    finalizedBy("koverHtmlReport")
+}
+
+kover {
+    reports {
+        total {
+            verify {
+                rule {
+                    bound {
+                        aggregationForGroup = AggregationType.COVERED_PERCENTAGE
+                        coverageUnits = CoverageUnit.LINE
+                        minValue = 92
+                    }
+                    bound {
+                        aggregationForGroup = AggregationType.COVERED_PERCENTAGE
+                        coverageUnits = CoverageUnit.BRANCH
+                        minValue = 86
+                    }
+                }
+            }
+        }
+    }
+}

core/src/main/kotlin/com/expediagroup/sdk/core/authentication/bearer/AbstractBearerAuthenticationManager.kt

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2024 Expedia, Inc.
+ *
+ * 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.
+ */
+
+package com.expediagroup.sdk.core.authentication.bearer
+
+import com.expediagroup.sdk.core.authentication.common.AuthenticationManager
+import com.expediagroup.sdk.core.authentication.common.Credentials
+import com.expediagroup.sdk.core.http.CommonMediaTypes
+import com.expediagroup.sdk.core.http.Method
+import com.expediagroup.sdk.core.http.Request
+import com.expediagroup.sdk.core.http.RequestBody
+
+/**
+ * Abstract class that contains common functionalities to store and renew bearer tokens.
+ * This class does not handle the bearer token fetching or parsing. Subclasses have to implement the
+ * [AuthenticationManager.authenticate] method where the token is fetched and parsed.
+ */
+abstract class AbstractBearerAuthenticationManager(
+    private val authUrl: String,
+    protected val credentials: Credentials,
+) : AuthenticationManager {
+    @Volatile
+    private var bearerTokenStorage = BearerTokenStorage.empty
+
+    /**
+     * Checks if the current bearer token is about to expire and needs renewal.
+     *
+     * @return `true` if the token is near expiration, `false` otherwise.
+     */
+    fun isTokenAboutToExpire(): Boolean =
+        run {
+            bearerTokenStorage.isAboutToExpire()
+        }
+
+    /**
+     * Clears the stored authentication token.
+     *
+     * This method resets the internal token storage, effectively invalidating the current session.
+     */
+    override fun clearAuthentication() =
+        run {
+            bearerTokenStorage = BearerTokenStorage.empty
+        }
+
+    /**
+     * Retrieves the stored token formatted as an `Authorization` header value.
+     *
+     * @return The token in the format `Bearer <token>` for use in HTTP headers.
+     */
+    fun getAuthorizationHeaderValue(): String =
+        run {
+            bearerTokenStorage.getAuthorizationHeaderValue()
+        }
+
+    /**
+     * Creates an HTTP request to fetch a new bearer token from the authentication server.
+     *
+     * @return A [Request] object configured with the necessary headers and parameters.
+     */
+    fun buildAuthenticationRequest(): Request =
+        run {
+            Request
+                .Builder()
+                .url(authUrl)
+                .method(Method.POST)
+                .body(
+                    RequestBody
+                        .create(mapOf("grant_type" to "client_credentials")),
+                ).setHeader("Authorization", credentials.encodeBasic())
+                .setHeader("Content-Type", CommonMediaTypes.APPLICATION_FORM_URLENCODED.toString())
+                .build()
+        }
+
+    /**
+     * Stores the retrieved token in internal storage for subsequent use.
+     *
+     * @param bearerTokenResponse The [BearerTokenResponse] containing the token and its expiration time.
+     */
+    fun storeToken(bearerTokenResponse: BearerTokenResponse) =
+        run {
+            bearerTokenStorage =
+                BearerTokenStorage.create(
+                    accessToken = bearerTokenResponse.accessToken,
+                    expiresIn = bearerTokenResponse.expiresIn,
+                )
+        }
+}

core/src/main/kotlin/com/expediagroup/sdk/core/authentication/bearer/BearerAuthenticationAsyncManager.kt

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2024 Expedia, Inc.
+ *
+ * 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.
+ */
+
+package com.expediagroup.sdk.core.authentication.bearer
+
+import com.expediagroup.sdk.core.authentication.common.Credentials
+import com.expediagroup.sdk.core.exception.service.ExpediaGroupAuthException
+import com.expediagroup.sdk.core.http.Request
+import com.expediagroup.sdk.core.http.Response
+import com.expediagroup.sdk.core.logging.LoggerDecorator
+import com.expediagroup.sdk.core.pipeline.ExecutionPipeline
+import com.expediagroup.sdk.core.pipeline.step.RequestHeadersStep
+import com.expediagroup.sdk.core.pipeline.step.RequestLoggingStep
+import com.expediagroup.sdk.core.pipeline.step.ResponseLoggingStep
+import com.expediagroup.sdk.core.transport.AbstractAsyncRequestExecutor
+import com.expediagroup.sdk.core.transport.AsyncTransport
+import org.slf4j.LoggerFactory
+import java.util.concurrent.CompletableFuture
+
+/**
+ * Manages bearer tokens fetching, parsing, storing, and renewal.
+ * This async implementation uses the injected [AsyncTransport] to make the authentication requests.
+ * Typically, this async implementation should be used with async SDK calls where the [AsyncTransport] is already
+ * configured and used to handle requests.
+ */
+class BearerAuthenticationAsyncManager(
+    authUrl: String,
+    credentials: Credentials,
+    private val asyncTransport: AsyncTransport,
+) : AbstractBearerAuthenticationManager(authUrl, credentials) {
+    private val requestExecutor =
+        object : AbstractAsyncRequestExecutor(asyncTransport) {
+            override val executionPipeline =
+                ExecutionPipeline(
+                    requestPipeline =
+                        listOf(
+                            RequestHeadersStep(),
+                            RequestLoggingStep(logger),
+                        ),
+                    responsePipeline =
+                        listOf(
+                            ResponseLoggingStep(logger),
+                        ),
+                )
+        }
+
+    /**
+     * Initiates authentication to obtain a new bearer token.
+     *
+     * This method sends a request to the authentication server, parses the response, and
+     * stores the token for future use.
+     */
+    override fun authenticate() {
+        try {
+            clearAuthentication()
+            executeAuthenticationRequest(buildAuthenticationRequest())
+                .thenApply { BearerTokenResponse.parse(it) }
+                .thenAccept { storeToken(it) }
+                .join()
+        } catch (e: Exception) {
+            throw ExpediaGroupAuthException(message = "Authentication Failed", cause = e)
+        }
+    }
+
+    /**
+     * Executes the authentication request and validates the response.
+     */
+    private fun executeAuthenticationRequest(request: Request): CompletableFuture<Response> =
+        requestExecutor
+            .execute(request)
+            .thenApply {
+                if (it.isSuccessful) {
+                    it
+                } else {
+                    throw ExpediaGroupAuthException("Received unsuccessful authentication response: [${it.status}]")
+                }
+            }.exceptionally {
+                throw it
+            }
+
+    companion object {
+        private val logger = LoggerDecorator(LoggerFactory.getLogger(this::class.java.enclosingClass))
+    }
+}