Build streaming ETL pipeline: Postgres → Parquet/S3 using Doobie, FS2, and Parquet4s

.github/workflows/ci.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: sbtscala/scala-sbt:eclipse-temurin-alpine-25.0.1_8_1.11.7_3.7.4
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Cache SBT
+        uses: actions/cache@v4
+        with:
+          path: |
+            /root/.ivy2/cache
+            /root/.sbt
+            /root/.coursier
+          key: sbt-cache-${{ runner.os }}-${{ hashFiles('**/build.sbt') }}
+          restore-keys: |
+            sbt-cache-${{ runner.os }}-
+
+      - name: Run scalafmt check
+        run: sbt scalafmtCheckAll
+
+      - name: Run scalafix check
+        run: sbt "scalafixAll --check"
+
+      - name: Run tests with coverage
+        run: |
+          sbt coverage test coverageReport
+
+      - name: Upload coverage report artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-report
+          path: target/scala-3.7.4/scoverage-report
+
+

.gitignore

@@ -3,3 +3,36 @@
 
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
+
+# SBT
+target/
+project/target/
+project/project/
+.bsp/
+
+# Scala-IDE specific
+.scala_dependencies
+.worksheet
+.cache
+.cache-main
+.cache-tests
+
+# IntelliJ
+.idea/
+*.iml
+*.iws
+*.ipr
+out/
+
+# VS Code
+.vscode/
+.metals/
+.bloop/
+metals.sbt
+
+# Mac
+.DS_Store
+
+# Docker volumes
+postgres_data/
+localstack_data/

.scalafix.conf

@@ -0,0 +1,23 @@
+rules = [
+  ExplicitResultTypes,
+  OrganizeImports,
+  RemoveUnused,
+  LeakingImplicitClassVal,
+  DisableSyntax,
+  NoAutoTupling,
+  NoValInForComprehension,
+  RedundantSyntax,
+  ProcedureSyntax
+]
+
+OrganizeImports {
+  groups = [
+    "scala.*",
+    "java.*",
+    "javax.*",
+    "org.*",
+    "com.*"
+  ]
+  removeUnused = true
+  targetDialect = "Scala3"
+}

.scalafmt.conf

@@ -0,0 +1,4 @@
+version = 3.9.4
+encoding = UTF-8
+runner.dialect = scala3
+