fix(zed): fix settings JSON parsing with base64 encoding (#604)

## Problem

The Zed module's settings parsing was broken. The previous
implementation used quote escaping:

```hcl
SETTINGS_JSON='${replace(var.settings, "\"", "\\\"")}'
```

This produced invalid JSON like `{\"theme\":\"dark\"}` which **jq could
not parse** because the backslash-escaped quotes are not valid JSON
syntax.

## Solution

Changed to use base64 encoding internally:

```hcl
locals {
  settings_b64 = var.settings != "" ? base64encode(var.settings) : ""
}

# In the script:
SETTINGS_B64='${local.settings_b64}'
SETTINGS_JSON="$(echo -n "${SETTINGS_B64}" | base64 -d)"
```

**User interface remains the same** - users still provide plain JSON via
`jsonencode()` or heredoc:

```hcl
module "zed" {
  source   = "..."
  agent_id = coder_agent.main.id
  settings = jsonencode({
    theme    = "dark"
    fontSize = 14
  })
}
```

## Testing

Added comprehensive tests:

**Terraform tests (5):**
- URL generation (default, folder, agent_name)
- Settings base64 encoding verification
- Empty settings edge case

**Container e2e tests (3):**
- Creates settings file with correct JSON (including special chars:
quotes, backslashes, URLs)
- Merges with existing settings via jq
- Exits early with empty settings

Also fixed existing tests to use `override_data` for proper workspace
mocking.

---------

Signed-off-by: Muhammad Atif Ali <me@matifali.dev>
Co-authored-by: DevCats <christofer@coder.com>

registry/coder/modules/zed/README.md

@@ -19,7 +19,7 @@ Zed is a high-performance, multiplayer code editor from the creators of Atom and
 module "zed" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/zed/coder"
-  version  = "1.1.3"
+  version  = "1.1.4"
   agent_id = coder_agent.main.id
 }
 ```
@@ -32,7 +32,7 @@ module "zed" {
 module "zed" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/zed/coder"
-  version  = "1.1.3"
+  version  = "1.1.4"
   agent_id = coder_agent.main.id
   folder   = "/home/coder/project"
 }
@@ -44,7 +44,7 @@ module "zed" {
 module "zed" {
   count        = data.coder_workspace.me.start_count
   source       = "registry.coder.com/coder/zed/coder"
-  version      = "1.1.3"
+  version      = "1.1.4"
   agent_id     = coder_agent.main.id
   display_name = "Zed Editor"
   order        = 1
@@ -57,7 +57,7 @@ module "zed" {
 module "zed" {
   count      = data.coder_workspace.me.start_count
   source     = "registry.coder.com/coder/zed/coder"
-  version    = "1.1.3"
+  version    = "1.1.4"
   agent_id   = coder_agent.main.id
   agent_name = coder_agent.example.name
 }
@@ -73,7 +73,7 @@ You can declaratively set/merge settings with the `settings` input. Provide a JS
 module "zed" {
   count    = data.coder_workspace.me.start_count
   source   = "registry.coder.com/coder/zed/coder"
-  version  = "1.1.3"
+  version  = "1.1.4"
   agent_id = coder_agent.main.id
 
   settings = jsonencode({
@@ -85,6 +85,7 @@ module "zed" {
         env     = {}
       }
 
+
     }
   })
 }

registry/coder/modules/zed/main.test.ts

@@ -1,5 +1,9 @@
 import { describe, expect, it } from "bun:test";
 import {
+  execContainer,
+  findResourceInstance,
+  removeContainer,
+  runContainer,
   runTerraformApply,
   runTerraformInit,
   testRequiredVariables,
@@ -12,66 +16,114 @@ describe("zed", async () => {
     agent_id: "foo",
   });
 
-  it("default output", async () => {
+  it("creates settings file with correct JSON", async () => {
+    const settings = {
+      theme: "One Dark",
+      buffer_font_size: 14,
+      vim_mode: true,
+      telemetry: {
+        diagnostics: false,
+        metrics: false,
+      },
+      // Test special characters: single quotes, backslashes, URLs
+      message: "it's working",
+      path: "C:\\Users\\test",
+      api_url: "https://api.example.com/v1?token=abc&user=test",
+    };
+
     const state = await runTerraformApply(import.meta.dir, {
       agent_id: "foo",
+      settings: JSON.stringify(settings),
     });
-    expect(state.outputs.zed_url.value).toBe("zed://ssh/default.coder");
 
-    const coder_app = state.resources.find(
-      (res) => res.type === "coder_app" && res.name === "zed",
-    );
+    const instance = findResourceInstance(state, "coder_script");
+    const id = await runContainer("alpine:latest");
 
-    expect(coder_app).not.toBeNull();
-    expect(coder_app?.instances.length).toBe(1);
-    expect(coder_app?.instances[0].attributes.order).toBeNull();
-  });
+    try {
+      const result = await execContainer(id, ["sh", "-c", instance.script]);
+      expect(result.exitCode).toBe(0);
+
+      const catResult = await execContainer(id, [
+        "cat",
+        "/root/.config/zed/settings.json",
+      ]);
+      expect(catResult.exitCode).toBe(0);
+
+      const written = JSON.parse(catResult.stdout.trim());
+      expect(written).toEqual(settings);
+    } finally {
+      await removeContainer(id);
+    }
+  }, 30000);
+
+  it("merges settings with existing file when jq available", async () => {
+    const existingSettings = {
+      theme: "Solarized Dark",
+      vim_mode: true,
+    };
+
+    const newSettings = {
+      theme: "One Dark",
+      buffer_font_size: 14,
+    };
 
-  it("adds folder", async () => {
     const state = await runTerraformApply(import.meta.dir, {
       agent_id: "foo",
-      folder: "/foo/bar",
+      settings: JSON.stringify(newSettings),
     });
-    expect(state.outputs.zed_url.value).toBe("zed://ssh/default.coder/foo/bar");
-  });
 
-  it("expect order to be set", async () => {
+    const instance = findResourceInstance(state, "coder_script");
+    const id = await runContainer("alpine:latest");
+
+    try {
+      // Install jq and create existing settings file
+      await execContainer(id, ["apk", "add", "--no-cache", "jq"]);
+      await execContainer(id, ["mkdir", "-p", "/root/.config/zed"]);
+      await execContainer(id, [
+        "sh",
+        "-c",
+        `echo '${JSON.stringify(existingSettings)}' > /root/.config/zed/settings.json`,
+      ]);
+
+      const result = await execContainer(id, ["sh", "-c", instance.script]);
+      expect(result.exitCode).toBe(0);
+
+      const catResult = await execContainer(id, [
+        "cat",
+        "/root/.config/zed/settings.json",
+      ]);
+      expect(catResult.exitCode).toBe(0);
+
+      const merged = JSON.parse(catResult.stdout.trim());
+      expect(merged.theme).toBe("One Dark"); // overwritten
+      expect(merged.buffer_font_size).toBe(14); // added
+      expect(merged.vim_mode).toBe(true); // preserved
+    } finally {
+      await removeContainer(id);
+    }
+  }, 30000);
+
+  it("exits early with empty settings", async () => {
     const state = await runTerraformApply(import.meta.dir, {
       agent_id: "foo",
-      order: "22",
+      settings: "",
     });
 
-    const coder_app = state.resources.find(
-      (res) => res.type === "coder_app" && res.name === "zed",
-    );
+    const instance = findResourceInstance(state, "coder_script");
+    const id = await runContainer("alpine:latest");
 
-    expect(coder_app).not.toBeNull();
-    expect(coder_app?.instances.length).toBe(1);
-    expect(coder_app?.instances[0].attributes.order).toBe(22);
-  });
+    try {
+      const result = await execContainer(id, ["sh", "-c", instance.script]);
+      expect(result.exitCode).toBe(0);
 
-  it("expect display_name to be set", async () => {
-    const state = await runTerraformApply(import.meta.dir, {
-      agent_id: "foo",
-      display_name: "Custom Zed",
-    });
-
-    const coder_app = state.resources.find(
-      (res) => res.type === "coder_app" && res.name === "zed",
-    );
-
-    expect(coder_app).not.toBeNull();
-    expect(coder_app?.instances.length).toBe(1);
-    expect(coder_app?.instances[0].attributes.display_name).toBe("Custom Zed");
-  });
-
-  it("adds agent_name to hostname", async () => {
-    const state = await runTerraformApply(import.meta.dir, {
-      agent_id: "foo",
-      agent_name: "myagent",
-    });
-    expect(state.outputs.zed_url.value).toBe(
-      "zed://ssh/myagent.default.default.coder",
-    );
-  });
+      // Settings file should not be created
+      const catResult = await execContainer(id, [
+        "cat",
+        "/root/.config/zed/settings.json",
+      ]);
+      expect(catResult.exitCode).not.toBe(0);
+    } finally {
+      await removeContainer(id);
+    }
+  }, 30000);
 });

registry/coder/modules/zed/main.tf

@@ -65,6 +65,7 @@ locals {
   owner_name     = lower(data.coder_workspace_owner.me.name)
   agent_name     = lower(var.agent_name)
   hostname       = var.agent_name != "" ? "${local.agent_name}.${local.workspace_name}.${local.owner_name}.coder" : "${local.workspace_name}.coder"
+  settings_b64   = var.settings != "" ? base64encode(var.settings) : ""
 }
 
 resource "coder_script" "zed_settings" {
@@ -75,7 +76,11 @@ resource "coder_script" "zed_settings" {
   script       = <<-EOT
     #!/usr/bin/env bash
     set -eu
-    SETTINGS_JSON='${replace(var.settings, "\"", "\\\"")}'
+    SETTINGS_B64='${local.settings_b64}'
+    if [ -z "$${SETTINGS_B64}" ]; then
+      exit 0
+    fi
+    SETTINGS_JSON="$(echo -n "$${SETTINGS_B64}" | base64 -d)"
     if [ -z "$${SETTINGS_JSON}" ] || [ "$${SETTINGS_JSON}" = "{}" ]; then
       exit 0
     fi

registry/coder/modules/zed/zed.tftest.hcl

@@ -5,6 +5,20 @@ run "default_output" {
     agent_id = "foo"
   }
 
+  override_data {
+    target = data.coder_workspace.me
+    values = {
+      name = "default"
+    }
+  }
+
+  override_data {
+    target = data.coder_workspace_owner.me
+    values = {
+      name = "default"
+    }
+  }
+
   assert {
     condition     = output.zed_url == "zed://ssh/default.coder"
     error_message = "zed_url did not match expected default URL"
@@ -19,6 +33,20 @@ run "adds_folder" {
     folder   = "/foo/bar"
   }
 
+  override_data {
+    target = data.coder_workspace.me
+    values = {
+      name = "default"
+    }
+  }
+
+  override_data {
+    target = data.coder_workspace_owner.me
+    values = {
+      name = "default"
+    }
+  }
+
   assert {
     condition     = output.zed_url == "zed://ssh/default.coder/foo/bar"
     error_message = "zed_url did not include provided folder path"
@@ -33,8 +61,54 @@ run "adds_agent_name" {
     agent_name = "myagent"
   }
 
+  override_data {
+    target = data.coder_workspace.me
+    values = {
+      name = "default"
+    }
+  }
+
+  override_data {
+    target = data.coder_workspace_owner.me
+    values = {
+      name = "default"
+    }
+  }
+
   assert {
     condition     = output.zed_url == "zed://ssh/myagent.default.default.coder"
     error_message = "zed_url did not include agent_name in hostname"
   }
 }
+
+run "settings_base64_encoding" {
+  command = apply
+
+  variables {
+    agent_id = "foo"
+    settings = jsonencode({
+      theme    = "dark"
+      fontSize = 14
+    })
+  }
+
+  # Verify settings are base64 encoded (eyJ = base64 prefix for JSON starting with {")
+  assert {
+    condition     = can(regex("SETTINGS_B64='eyJ", coder_script.zed_settings.script))
+    error_message = "settings should be base64 encoded in the script"
+  }
+}
+
+run "empty_settings" {
+  command = apply
+
+  variables {
+    agent_id = "foo"
+    settings = ""
+  }
+
+  assert {
+    condition     = can(regex("SETTINGS_B64=''", coder_script.zed_settings.script))
+    error_message = "empty settings should result in empty SETTINGS_B64"
+  }
+}