Activate default environment instead of base environment

.github/workflows/example-16.yml

@@ -0,0 +1,157 @@
+name: "Example 16: Default environment activation"
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+  schedule:
+    # Note that cronjobs run on master/main by default
+    - cron: "0 0 * * *"
+
+jobs:
+  example-16-build:
+    # prevent cronjobs from running on forks
+    if:
+      (github.event_name == 'schedule' && github.repository ==
+      'conda-incubator/setup-miniconda') || (github.event_name != 'schedule')
+    name:
+      Build Ex16 (os=${{matrix.os}}, default env=${{ matrix.add-activation-env
+      == 'true' && 'default' || 'base' }})
+    runs-on: ${{ matrix.os }}-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        add-activation-env: ["false", "true"]
+        os: ["ubuntu", "windows"]
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+
+      - name: Set up Miniconda for installer builds
+        uses: ./
+        with:
+          activate-environment: ""
+          auto-activate: false
+
+      - name: Create installer
+        uses: conda-incubator/installer@2d2df0b03c6795f70e128c56403c7d084cca4fb8 # v0.1.0
+        id: create-installer
+        with:
+          conda-root: ${{ env.CONDA }}
+          environment-yaml-string: |
+            channels:
+              - conda-forge
+            dependencies:
+              - constructor
+            variables:
+              ADD_ACTIVATION_ENV: '${{ matrix.add-activation-env }}'
+              EXT: ${{ matrix.os == 'windows' && 'exe' || 'sh' }}
+          input-directory: etc/example-installers/default-environment/
+
+      - name: Upload installer to Github artifact
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          path: ${{ steps.create-installer.outputs.artifacts-directory }}/*
+          name:
+            ex16-${{ matrix.os }}-${{ matrix.add-activation-env == 'false' &&
+            'no-' }}-activation-env
+
+  example-16-test:
+    needs: [example-16-build]
+    name:
+      Test Ex16 (os=${{matrix.os}}, default env=${{ matrix.add-activation-env ==
+      'true' && 'default' || 'base' }}, auto-activate-base=${{
+      matrix.auto-activate-base }})
+    runs-on: ${{ matrix.os }}-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        auto-activate-base: ["false", "true"]
+        add-activation-env: ["false", "true"]
+        os: ["ubuntu", "windows"]
+    steps:
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+
+      - name: Obtain artifact
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
+        with:
+          name:
+            ex16-${{ matrix.os }}-${{ matrix.add-activation-env == 'false' &&
+            'no-' }}-activation-env
+          path: ${{ runner.temp }}/_installer
+
+      - name: Determine installer file name
+        id: installer-file
+        env:
+          ARTIFACTS_DIRECTORY: ${{ runner.temp }}/_installer
+          EXT: ${{ matrix.os == 'windows' && 'exe' || 'sh' }}
+        run: |
+          INSTALLER_FILE=$(find "${ARTIFACTS_DIRECTORY}" -name "*.${EXT}" | head -n 1)
+          echo "installer-file=${INSTALLER_FILE}" >> ${GITHUB_OUTPUT}
+        shell: bash
+
+      - name: Run installation
+        uses: ./
+        with:
+          activate-environment: ""
+          auto-activate-base:
+            ${{ matrix.auto-activate-base == 'true' && 'true' ||
+            'legacy-placeholder' }}
+          auto-activate:
+            ${{ matrix.auto-activate-base == 'true' && '' || 'true' }}
+          installation-dir: ${{ runner.temp }}/installer_test
+          installer-url:
+            file://${{ steps.installer-file.outputs.installer-file }}
+
+      - name: Output conda info (bash)
+        env:
+          DEFAULT_ENV: ${{ matrix.add-activation-env && 'default' || 'base' }}
+          TEST_DIR: ${{ runner.temp }}/installer_output
+        run: |
+          mkdir -p ${TEST_DIR}
+          conda info --json > "${TEST_DIR}/bash.json"
+        shell: bash -el {0}
+
+      - name: Output conda info (cmd.exe)
+        if: matrix.os == 'windows'
+        env:
+          TEST_DIR: ${{ runner.temp }}\installer_output
+        run: |
+          conda info --json > "%TEST_DIR%\cmd.exe.json"
+        shell: cmd /C CALL {0}
+
+      - name: Output conda info (PowerShell)
+        if: matrix.os == 'windows'
+        env:
+          TEST_DIR: ${{ runner.temp }}\installer_output
+        run: conda info --json > "${env:TEST_DIR}\pwsh.json"
+        shell: pwsh
+
+      - name: Test default environments
+        env:
+          DEFAULT_ENV:
+            ${{ matrix.add-activation-env == 'true' && matrix.auto-activate-base
+            == 'false' && 'default' || 'base' }}
+          TEST_DIR: ${{ runner.temp }}/installer_output
+        run: |
+          import json
+          import os
+          from pathlib import Path
+
+          json_dir = Path(os.environ["TEST_DIR"])
+          default_env_expected = os.environ["DEFAULT_ENV"]
+          incorrect_environments = {}
+          for file in json_dir.iterdir():
+              conda_info = json.loads(file.read_text())
+              default_env = conda_info.get("active_prefix_name")
+              if default_env != default_env_expected:
+                  incorrect_environments[str(file.name).removesuffix(".json")] = default_env
+          if incorrect_environments:
+              raise AssertionError(
+                  f"Found incorrect default environments: {incorrect_environments}"
+              )
+        shell: python

.github/workflows/example-3.yml

@@ -38,7 +38,7 @@ jobs:
           environment-file: etc/example-environment.yml
           python-version: 3.8
           condarc-file: etc/example-condarc.yml
-          auto-activate-base: false
+          auto-activate: false
           auto-update-conda: true
       - run: |
           conda info
@@ -60,7 +60,7 @@ jobs:
           environment-file: etc/example-environment-no-name.yml
           python-version: 3.8
           condarc-file: etc/example-condarc.yml
-          auto-activate-base: false
+          auto-activate: false
           auto-update-conda: true
       - run: |
           conda info

README.md

@@ -61,6 +61,7 @@ possibility of automatically activating the `test` environment on all shells.
 | [Apple Silicon](#example-13-apple-silicon)                         | [![Apple Silicon][ex13-badge]][ex13]                            |
 | [Remove defaults](#example-14-remove-defaults-channel)             | [![Remove defaults][ex14-badge]][ex14]                          |
 | [Linux ARM](#example-15-linux-arm)                                 | [![Linux ARM][ex15-badge]][ex15]                                |
+| Default environments                                               | [![Default environments][ex16-badge]][ex16]                     |
 
 [ex1]:
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-1.yml
@@ -122,6 +123,10 @@ possibility of automatically activating the `test` environment on all shells.
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-15.yml
 [ex15-badge]:
   https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-15.yml/badge.svg?branch=main
+[ex16]:
+  https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-16.yml
+[ex16-badge]:
+  https://github.com/conda-incubator/setup-miniconda/actions/workflows/example-16.yml/badge.svg?branch=main
 
 ## Other Workflows
 
@@ -180,16 +185,16 @@ Miniconda installation.
 
 ### Activate `base` environment
 
-If your specific workflow still needs to activate and use `base` you will need
-to do **both** of:
+If your specific workflow still needs to activate and use the default
+environment, you will need to do **both**:
 
 - set `activate-environment` to an empty string
-- set `auto-activate-base` to `true`
+- set `auto-activate` to `true`
 
 ```yaml
 - uses: conda-incubator/setup-miniconda@v3
   with:
-    auto-activate-base: true
+    auto-activate: true
     activate-environment: ""
 ```
 
@@ -330,7 +335,7 @@ jobs:
           environment-file: etc/example-environment.yml
           python-version: 3.5
           condarc-file: etc/example-condarc.yml
-          auto-activate-base: false
+          auto-activate: false
       - run: |
           conda info
           conda list

action.yml

@@ -134,16 +134,27 @@ inputs:
       for more information.'
     required: false
     default: ""
-  auto-activate-base:
+  auto-activate:
     description:
-      'Conda configuration. If you’d prefer that conda’s base environment not be
-      activated on startup, set the to "false". Default is "true". This setting
-      always overrides if set to "true" or "false". If you want to use the
-      "condarc-file" setting pass and empty string. See
+      'Conda configuration. If you’d prefer that conda’s default environment not
+      be activated on startup, set the to "false". Default is "true". This
+      setting always overrides if set to "true" or "false". If you want to use
+      the "condarc-file" setting pass an empty string. See
       https://docs.conda.io/projects/conda/en/latest/user-guide/configuration/
       for more information.'
     required: false
     default: "true"
+  auto-activate-base:
+    description:
+      (deprecated in favor of `auto-activate`) 'Conda configuration. If you’d
+      prefer that conda’s base environment not be activated on startup, set the
+      to "false". Default is "true". This setting always overrides if set to
+      "true" or "false". If you want to use the "condarc-file" setting pass an
+      empty string. See
+      https://docs.conda.io/projects/conda/en/latest/user-guide/configuration/
+      for more information.'
+    required: false
+    default: "legacy-placeholder"
   auto-update-conda:
     description:
       'Conda configuration. When "true", conda updates itself any time a user